How do bats feed their babies

Bats regurgitate nectar for their babies—a new discovery

A Pallas' long-tongued bat feeds on nectar. Females of this species have a never-before-recorded method of feeding their young.

Photograph by Christian Ziegler, Nat Geo Image Collection

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Any human mom can attest that keeping a baby fed and happy can be a Herculean task. That’s why some animal mothers have evolved some truly creative—and sometimes surprising—strategies.

For instance, all mammals produce milk for their babies, but several species also give their offspring food off their plate, so to speak. (See photos of animal mothers and babies.)

Take Pallas’ long-tongued bat (Glossophaga soricina), a Central and South American bat that visits flowers to feed on nectar, just like a hummingbird. As scientists recently reported in a new study, these moms, in addition to milk, feed their pups regurgitated nectar. Baby bats lick at their mothers’ mouths and their moms oblige by vomiting up a sweet meal for them. It’s the first evidence for mouth-to-mouth feeding in nectar bats.

Co-author Andreas Rose, an ecologist at Germany’s University of Ulm, says the finding raises some intriguing questions.

“Is it less energy demanding for mothers to directly feed nectar to their pups instead of producing milk?” Rose says by email.

It’s also possible the behavior has non-nutritional benefits for bat babies, such as transferring gut microbes or helping them learn the social processes around eating.

Beyond bats, other animals—like fish, reptiles, and invertebrates—make mammalian baby food seem positively pedestrian. Here are some examples of unusual things parents feed their offspring.

Fish give mucus to their young

For most fish, parenting duties end when their young hatch. But a group of cichlid fish native to the Amazon River, called discus fish, act more like mammalian mothers, caring for their fry.

Blue discus (Symphysodon aequifasciatus) babies feed on mucus from a parent's body in Japan.

Photograph by Fumitoshi Mori, Minden Pictures

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Both mom and dad feed their young mucus that’s secreted all over their bodies. This behavior can last for up to a month, until the young fish are old enough to forage on their own.

What’s more, the nutritional and immunological content of the mucus changes as the young develop, much like mammalian milk. (Read how animal mothers remind us a lot of our own.)

Snake moms dine on toxic toads

The tiger keelback snake (Rhabdophis tigrinus) makes itself poisonous by eating toads and storing their defensive compounds in specialized structures on its neck. Mothers pass these toxins on to their babies via the egg and yolk, chemically arming the baby snakes before they hatch.

When pregnant, female snakes seem to deliberately seek out poisonous prey. Poisonous toads are rarer than their everyday prey, so it’s energetically costly to seek them out. But these moms put in the effort so their babies are as poisonous as possible from day one.

Spiders provide “milk” for their babies

The mothers of a species of jumping spider native to Japan (Toxeus magnus) feed a milk-like substance to their spiderlings for weeks after they hatch.

Spiderlings drink this milk, which contains nearly four times the protein of cow’s milk, from the surface of the nest and directly from their mother’s body.

Mother spiders continue to care for and feed their offspring for more than a month, until the little ones are almost fully mature.

Caecilian moms feed young their own skin

A caeclian female curls up with her young. These babies tear off and feed on their mother's skin, which regrows every three days.

Photograph by Hilary Jeffkins, Nature Picture Library

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In a few species of worm-like amphibians called caecilians, babies eat the fatty skin off their mom’s back. After laying their eggs, a nutrient-rich, fatty outer layer of skin forms on caecilian moms. The babies, born with a specialized set of teeth, scrape this layer off and eat it.

Researchers found that in the week after their offspring hatched, mother caecilians lost about one-seventh of their body weight to their hungry babies.

The ultimate maternal sacrifice

In some species of insects and arachnids, mothers literally die for their young. It’s called matriphagy—literally, mother-eating. Letting your babies feast on your nutritious body enhances their chances of survival. (Neither cute nor cuddly: These animal babies are wee monsters.)

The velvet spider Stegodyphus lineatus feeds her young by regurgitating liquid food for about two weeks. Then her babies kill and consume her.

One study found that after laying eggs, females begin to digest their own bodies. Just before her young eat her, much of the female’s abdomen is liquified.

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How Many Babies Do Bats Have?

Just like all mammals, bats have a gestation period, which is the time between conception and birth. Most bat species give live birth to only one pup per year. However, some species can give birth to twins.

When the baby bat is born it weighs about one-third of its mother’s weight and the newborn pup hangs on tightly with their hind claws while hanging upside down by their mouths which are suckling from her nipple. Most mothers do not leave the roost until they have taught the pup how to fly properly at around five weeks old because they are still too small for them to be left unattended in the wild during this time period. In this article, we will answer some of the most common questions about bat babies!

How many babies do bats have

Most bats give birth to one baby pup a year. Other species, like the hoary bat, can have as many as four. For 3 to 4 weeks, the baby is incapable of flying and is latched onto its mother’s nipple. It is not until they are about five weeks old that the baby bat can begin flying lessons and leaves its roost.

When do bats have babies

Bats have what we call a Maternity season, which is the time of year when female bats give birth to bat babies. This maternal season usually takes place around May 15 to August 15 but may vary depending on the species, climate, and where the bats live. During this season, female bats give birth to baby bats and the whole colony is occupied with taking care of the young, usually taking turns raising and feeding them.

Bat Calendar

Bats’ reproduction cycle is quite predictable, they don’t really deviate from this yearly pattern. Here’s a bat calendar to help you understand when the females are pregnant, giving birth, and caring for the young bats.

January and February – This time of the year, the bats are in hibernation. They are in their caves or mines and will not be seen until the spring comes around again when it is time for them to mate.

March – Depending on where they are and whether it’s still cold, they could wake up and come out of their hiding places or they may choose to stay and wait until warmer weather.

April – They will start emerging from their caves in search of food (insects). This is also when the breeding season begins.

May – The bats start forming colonies. Females create maternity colonies and male bats create bachelor colonies. You will start seeing pregnant female bats flying around your neighborhood at night in search of potential nesting sites such as attics or barns.

June – Females will start eating huge amounts of insects to prepare for the birthing season.

July – By this time, most of the female bats have given birth and now their main priority is taking care of the newborns by feeding them until they are able to fly on their own.

August – This is when baby bats start to learn how to fly and forage for food.

September-October – Bats are now busy looking for roosting sites and eating huge amounts of insects to prepare for winter hibernation.

November–December – Hibernation begins.

Bat maternity season and bat removal

During bats’ maternity season, it is illegal to conduct bat abatement from your home. Bats are protected during this time of year. There are flightless pups in the colony and if you remove the mothers, the baby bats will die since they are completely dependent on their mothers. The maternal season may be the most important time of year for these tiny mammals. If you do bat exclusion or harm/kill one during this critical period – it could land you stiff fines or even jail time. Most times, it is best to just let the maternal season pass and wait for the bats to move into their winter hibernaculum. Once the season passed you can start thinking about evicting them. If you need advice regarding bat infestation during this season, contact AAAC Wildlife Removal!

Colonies and Maternity Roost

In the maternal season, The females gather and create maternity roosts to give birth and raise their pups. The whole roost is occupied with looking after the baby bats and taking turns caring for them while other members of the colony hunt. After five weeks, when baby bats are big enough and can learn how to survive on their own, they leave along with adult colonies who will find a new place to live together.

How are baby bats born

Bats are mammals, so a female bat gives birth to a live baby and do not lay eggs. Astonishingly, females give birth while hanging upside down! The mother pushes her pup out of her womb towards her feet and then catch it to prevent it from falling to the ground. Once they’re out of the womb, their mothers will groom their pups and then move them onto her chest where they can suckle.

What are baby bats like ? 

Newborn bat pups weigh only two or three grams! They have no fur but instead have fine, downy hair. At this stage of development, the wings do not function well enough for flying so you will see the little ones hanging on to mom while its parent is feeding or roosting during the day with other baby bats clumped together.

How big are baby bats?

The newborn is only around 1 or 2 inches long when they come out of the womb. However, relative to the weight of the mother bat, they are quite heavy and can weigh as much as a third of the mother’s weight.

What do bats feed bat babies?

Just like all baby mammals, baby bats suckle milk from mother bats until they are weaned. Mother bats produce it to feed their young for about three weeks and the babies will drink them until they can fly on their own. Some species feed their young with regurgitated nectar where the pups lick at their mother’s mouth and the mother vomits a meal for the young to eat. Learn more about the strange things bats can do.

How do bats carry their babies?

Bat mothers are very protective of their young and they will go through a lot for them. The mother keeps her baby attached to a nipple inside her wings throughout its development until it becomes self-sufficient enough to live on its own, which could take up to six weeks or more depending on how old the pup is when it leaves mommy’s side. Large kinds such as the Big Brown bat hold and cradle babies within the fold of skin under its wing, while some species have special pockets near mammary glands to keep their pups safe.

How long do bats stay with their mothers?

In general, mothers stay with their young for about two months. This is to ensure that her baby’s immune system and other bodily functions are strong enough to survive on their own outside of the roost. During this time, the baby bats can drink milk and learn how to fly; they even attempt flying on their own while also trying out exploring/foraging food sources. Once a mother feels that her pup is ready-and-able to take care of itself independently (i.e., it’s self-sufficient), she will then leave her maternity roost in search of food exclusively for herself.

Baby bat nest in the attic

Many bat species make their habitat in homes. It is common for them to roost in crawlspaces or attics. When they are raising their young it can be difficult to remove them without causing harm. If you find that there’s been an infestation by bats in your home. Be sure to contact wildlife professionals. DIY removal is never a good idea as it may cause harm to the baby bats, not to mention you exposing yourself to the risk of disease from bat poop in the attic. If you come across a nest on your attic or rooftop call wildlife control services immediately before any more damage occurs.

Bat Removal Services

For professional and humane bat removal contact AAAC Wildlife Removal. We provide humane wildlife control for bats or other wild animals including raccoons, skunks, and snakes that can cause damage to your home or property. Our team is experienced and knowledgeable about local laws regarding animal trapping and exclusion so you can have peace of mind knowing these creatures won’t be back! If you have any questions about pups or bat removal in general, please feel free to contact us and we will be happy to assist you with your questions. We are available 24/7 for all of your bat control needs!


Are bats mammals?

Yes! Bats are the only that have evolved to fly. They belong to the order Chiroptera, one of several orders in class Mammalia (all mammals).

Do bats create nests?

Bats do not build nests, they create roosting sites. A roosting site is a place where a bat will sleep, rest or hibernate. Bat mothers and their young create maternity colonies in which they share these sites together during times of the year when mating takes place (May 15 to August 15).

What is a bat’s diet?

Bats eat fruit, nectar, and sometimes insects or other small animals that happen to cross their path while foraging at night. The lesser long-nosed bats feed on flower nectars or fruits.

Originally published on

Why a bat feeds its babies for a long time

During feeding, the food brought by the mother helps the offspring to recognize prey signals and deal with large insects.

When bats feed their young, they receive their first lessons in determining:

  • what prey is tasty;
  • how to recognize it with echolocation;
  • how to get large and quite capable of defense insects.

This was reported in the journal Animal Behavior by a group of scientists from Germany. nine0003

Lesser Great-eared Leaf-nosed Photo: © Geipel

For their study, Inga Geipel and Mirjam Knörnschild from the University of Ulm observed pairs of a mother and calf of the Lesser Great-eared Leaf-nosed (Micronycteris microtis). On the island of Barro Colorado in Panama, they filmed five pairs of bats at night with an infrared camera for several months. These animals live in groups of three to ten individuals. Females usually bring offspring in May, once a year, and then feed the babies with milk for several weeks. However, it was necessary to find out the following information about bats:

  • when the pups start eating solid food;
  • whether they catch it themselves.

"The videos show that mothers provide their children for about five more months after they stop feeding milk with whole insects. Some of them bring more than half of their prey to their babies," says Inga Gaipel. As the age of the animals increases, the amount of prey decreases. However, the mother feeds them, even if they are already able to fly and can hunt. Why? This was another bat riddle. nine0003

Echolocation training

Why do mothers spend so much effort? Biologists, observing the life of bats, suggested that when they transfer food, they teach the young to perceive the acoustic echo. The hunting strategy of this species of nocturnal mammals is very complex: bats seek prey in the dense vegetation of tropical forests and must filter out a lot of extraneous interference. Moreover, their main food often sits motionless on the leaves, making it difficult to determine its location. nine0003

In order to hunt successfully, young animals must be able to recognize the pattern of the characteristic acoustic echo of their prey. But no one has seen the cubs accompany their mothers on hunts and learn to echolocate their prey. As it turned out, young animals go through this phase of learning during the feeding period.

Mother passes food to her cub Photo: © Geipel

Eating behavior

Another reason for transferring prey may be quite practical: it is difficult for inexperienced adolescents to deal with fairly large insects. What do bats eat? In the menu of adults, which weigh 5-7 grams, there are dragonflies, grasshoppers or moths. Perhaps the mothers are training the cubs to handle this large prey. nine0003

Summing up, Inga Geipel and Miriam Knornschild conclude:

  1. It is very important that young animals learn to hunt large insects - this is what they can practice on prey transferred by their mother.
  2. Teenagers scan it during transmission using echolocation and get the first impression that the ultrasonic reflection signal pattern from this insect creates.

Thus, prolonged feeding of the small bat-eared bollard is probably a double advantage for young animals, writes

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Rearing of bats - Ukrainian Bat Rehabilitation Center

So, you have found a baby bat. Your actions:

  1. Carefully inspect the animal for injuries (swelling, bruising, fractures, etc.). If the bat has fractures or injuries, the help of a veterinarian will be needed.
  2. Determine the age of the cub . The age of the cub will depend on its diet and conditions of detention.
  3. Give water to drink, because often the animals are found dehydrated, and the first thing they need is clean boiled water.

Chiroptera are mammals, during the first month of life mothers feed them with milk. Baby bats are not able to fly at first (first mothers wear them on themselves, and then leave them in a shelter for the period of hunting for insects). Sometimes the cubs fall out of the shelter (or fall from the mother) and hide not far from it. If your foundling is not injured, not exhausted, and you can get to the shelter (attic of the house, hollow tree) from which he fell out, the best solution is to return him to his place. A baby bat is very difficult to feed for a lot of reasons, only his mother can do it perfectly. If you have such an opportunity, do it - quietly and gently plant the animal in the shelter. nine0003

How to determine the age of a baby bat

Below are photos of a baby bat of different ages using the example of two-tone leather on . They will serve you to determine the age of your foundling, as well as a guideline in its subsequent development. This cub was initially breastfed, that is, it was fed by its mother, therefore, the timing of the development of the animal may differ slightly on artificial feeding.

1 day:

- completely "bald"

- "blind"

- no teeth

- pay attention to the sides of the tummy, this is how a well-fed baby bat looks like

4 days:

- "blind" starts Make a wool at

9 days:

- eyes open

- withers, part of the back and stomach are covered with short wool

11 days:

- eyes are open

- the whole body is covered with short wool

- tiny teeth

14 days are noticeable:

- wool becomes longer than

- holding on to the wand, the cub waves wings, but does not jump, since it still does not know how to fly

20 days:

- wool rather long

— dark bases of hairs and light, like silver, tips are clearly visible; grayer than adults

- teeth are almost formed but smaller than adults


- well formed sharp teeth

General rules of care

Baby bats are best kept in a box or box with access to air and natural light (but not direct sunlight). Ordinary cages are often not suitable, as the animal can crawl between the twigs. It is a good idea to put and hang pieces of cloth in the shelter so that the animal can hide in them. If you can’t find a convenient box, then a small cloth bag will do. nine0003

Keep the animal out of the reach of pets and children!

Bats often have ectoparasites - ticks, fleas, etc. They are not dangerous for humans and domestic animals. If the animal is weak, does not wash itself or is heavily infected, it is necessary to help it get rid of the parasites. They can be removed with tweezers or a damp cotton swab. If you see a need for special treatments, please contact us for further advice.

Age 0 to 20 days


Such an animal needs to be kept warm. Maintain a constant temperature around 37 degrees. For this, thermal mats for animals or just a stable bottle of warm water wrapped in a towel (or sock) are suitable. But don't overheat!


Very young mice are fed goat's milk or special puppy formula (available at pet stores) prepared according to the recipe on the packaging. Cow's milk is not nutritious enough for baby bats, they will not be able to fully develop on it. The same applies to milk formulas for baby food - the animal lags behind in development. nine0003

It is very important that the milk is fresh, boiled and the mixture is prepared just before feeding. Do not leave the finished mixture until the next feeding. Do not add eggs or other ingredients to milk or formula - risk of intestinal infection and death. It is also undesirable to change one milk to another. Inventory must be well washed, sterilized or boiled.

Vitamin and mineral supplements are often needed, especially if you are feeding with milk rather than formula. Look in your pet stores for bird vitamin/mineral supplements without gastroliths (sand, pebbles, etc.). The dosage will depend on the selected complex. This question needs to be clarified individually with our specialists. nine0003

Feeding schedule

Babies are fed every 2-3 hours, day and night. Grown up - every 3-4 hours. If the animal did not have time to digest the previous portion, and this is noticeable by the enlarged tummy, increase the interval between feedings.

When feeding, hold the animal so that the head is slightly lower than the body. Then the spilled milk will not stain the little body. Feed the animal slowly.

With age, the interval between feedings increases.

Amount of food

Cubs of different species and even of different ages can differ significantly in weight, and therefore the amount of food they need is different. For this reason, we cannot clearly say how much your baby bat should eat.

If you know its weight, you can use the formula for calculating the approximate portion of food: weight of the animal in grams * 0.05 ml. So, for a serving for a 10-gram animal, 10 g * 0.05 ml \u003d 0.5 ml of milk or mixture will be required. We emphasize that this is an approximate portion, everything is individual. If the animal eats with appetite, and then begins to turn away, it means that he has eaten, do not be discouraged. nine0003

The portion of the food eaten is conveniently tracked by the scale on the syringe. It is very important not to overfeed the animal . Babies often cannot cope with large volumes of food, bloating begins, which often ends in death. Therefore, feed the animal in small portions, but often. For 1-2 days of observation, you will select portions and feeding regimen suitable for him.

Growing up, the animal eats more food, and the intervals between feedings increase.


Often the plastic tip of a syringe or pipette is too large for this purpose. A syringe (without a needle) is not bad, with a heat-shrink tube put on the spout (you can buy it at a hardware store).

Feeding with a Q-tip soaked in milk is sometimes suitable. The animal just sucks it. When feeding, it is important to ensure that the baby does not swallow air.


At this age, problems often occur with the intestines - stale food or too large a portion. The problems are very serious, it is important and requires attention. Examine the animal's tummy before eating - did the previous portion manage to be digested, is there any swelling, etc. If the animal gets dirty during feeding, wipe these places with a damp cotton swab. nine0003

Every time after eating, lightly massage his anus (butt) with a wet, warm cotton swab. This will encourage the baby to poop. This procedure is mandatory up to 2 weeks of age.

It is important to monitor the regularity and character of the stool of small bats - color, consistency. Normally, feces when breastfeeding are yellow, jelly-like. It's black, that's ok. But green indicates problems!


If the found animal is covered with hair, but after some time began to go bald, it means that there are not enough vitamins and minerals in the food. Most often, the first bald spots appear on the chin, abdomen. Also, normally there should be no curvature of the forearm or bones of the fingers. Therefore, periodically inspect the animal. Vitamin and mineral complexes for birds (without gastroliths) are suitable for bats. Contact us for further advice in case of such a problem. nine0003

It is convenient to monitor the growth dynamics of the cub by tracking its weight and measuring the length of the forearm. Make such notes daily, as bats grow very quickly. They will allow you to understand how well the diet is chosen and adjust it in time if the animal does not grow.

Normally, young bats at an early age most often sit in a shelter, sleep, eat, wash. From 7-10 days they begin to study the shelter and the world outside it. They are not yet capable of flying, they can only run on horizontal surfaces or climb vertical ones. nine0003

Age: more than 20 days

With a normal diet at this age, the cub is already covered with hair, his teeth grow. They are still smaller than in adult bats, but sufficient to chew on solid food, namely insects.


A 24-hour heating pad is not required. Warming is necessary only after feeding. The cub learns to regulate its body temperature - it cools down when it sleeps and warms up when it wakes up. Before feeding, you need to give the animal time to warm up. When warmed, the bat "trembles" all over. nine0003


Once your bat's teeth are big enough to chew on solid food, it's time to start feeding on insects. The larvae of the flour beetle are best suited for this. Complementary foods are introduced into the diet of the animal gradually. That is, the main food is still milk or a mixture.

The first evening of complementary feeding - let you try the pomace (innards) of flour beetle, no more than half of the insect, a couple of bites. Most likely, the animal will not understand that you are offering him food, since he has not encountered insects before. You will have to tear off the head of the insect and put a little entrails on the “lips” of the animal. When he licks them off, give him some more pomace. After that, you give a bit of food familiar to him - milk or a mixture. Do not leave the animal unattended, since mealworms are new food for the intestines, the animal is just learning to digest it, and there is a risk of problems with the tummy. Watch the chair and the behavior of the animal. Subsequent feedings are dairy, as usual. nine0003

The next evening, offer the baby bat a slightly larger portion of mealworm entrails. And so, for several days, increase the portion of pomace. When the animal begins to eat them willingly and digest them without problems, let him gnaw on the chitin of the flour beetle, quite a bit. Again, he still does not know how to chew, so he will do it awkwardly. Supplement with entrails or milk, and then again observe how the intestines react to new, more solid food. In the future, let the animal eat more and more pieces of flour beetle. nine0003

In this way, you will gradually teach the baby bat to eat and digest insects. When he successfully eats the mealworm and digests it, you can gradually increase the amount of mealworm in the diet while reducing the amount of milk or formula. Often these are evening and night feedings with insects, and morning and afternoon feedings with milk or a mixture.

Do not forget about vitamin and mineral complexes. A growing animal needs them every 2-3 days. The dosage is individual and depends on the complex itself and the weight of the bat. Contact our specialists. nine0003

If you have picked an animal at 3 weeks of age, have good teeth, but do not fly yet, feed it milk or formula for 2-3 days as described for mice aged 0 to 20 days. Only when the animal is digesting dairy food normally, start feeding insects, as described in this section.

Feeding regimen

An adult animal needs to be fed 5-6 times a day. These are evening and night feedings, as well as morning and afternoon feedings. When the animal is able to feed on insects, gradually remove daytime feedings. Having digested the morning portion of food, he should cool down and sleep until the evening. In the evening, when it gets dark, the animal will wake up on its own, warm up, and then it will be ready to warm up and eat.

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