11 Animal Species That Eat Their Own Young

Nature can be a cruel place. Disasters, predators, accidents, disease, and other assorted misfortunes and death dealers can lurk behind every corner. Unless the animal is so tough that it has no natural predators, it should be prepared for just about anything the day can throw at it. 

However, sometimes all the preparation in the world is simply not enough — especially if the animal is still young and comparatively helpless. Even if it tries its best to prepare against just about any outside threat imaginable, it might surprisingly fall victim to a bigger, stronger, and older member of its own species. 

This phenomenon of animals eating younger members of their own species is called filial cannibalism, and it's an unsettling but surprisingly important part of many animal species' behavior. It can happen for a variety of reasons, and may be either specific to a certain situation or just an unfortunate part of the species' everyday existence. Here are some animals that have been known to eat their young, and a look into the situations that might prompt them to do so.  

Readers who have had pet hamsters may have bumped into stories of these cute critters eating their own young. It's not just a horror story the Hamster Owners' Club likes to tell, either. It actually happens, but the reasons are a bit more convoluted than you might think. 

A hamster's pregnancy is a quick, life-changing thing thanks to its comparatively short time frame — about three weeks. They usually give birth to a horde of roughly 8-10 completely defenseless pups, though there may be even more. This means that a hamster finds itself in charge of a massive family in a relative blink of an eye, which in turn may trigger enough stress or fear for the animal to eat at least some of its babies. If a human handles the pups, their scent might also change, which could cause the mother hamster to perceive said pup as a fraudster and prompt a violent reaction. Poor diet may also affect a hamster's tendency to eat its pups. 

Hamsters eat their young outside captivity, too. In 2014, researcher Mathilde Tissier found that the hamsters whose diet consists largely of corn are far more likely to eat their young than ones with access to other food sources. This is because corn-based sustenance leaves them severely lacking in vitamin B3 (aka niacin), which gives them a potentially fatal malnutrition condition called pellagra, and causes them to instinctively seek nutrients wherever they can find them.

Animals don't kill and eat their young out of malice, but looking at how chimpanzees can go about this incredibly gruesome business, one might be tempted to think otherwise. It's not uncommon for male chimps to kill baby chimps if they get their hands on them, and the adult apes have even been known to eat the infants. Female chimpanzees have a tendency to steer clear from their group while giving birth and caring for their baby, and scientist suspect that this period of isolation is a strategic move that's specifically designed to prevent adult-on-baby violence from happening.  

At the end of the day, this disturbing behavior isn't quite as actively villainous as it seems to be from a human standpoint. Instead, it's connected to chimpanzee mating habits. The competition for procreation in chimp groups is extremely high, and killing a mother chimp's baby is a specific tactic that males use to get the female away from childcare and back in the mating game. Nature — it can be very, very cruel sometimes. 

The ultimate predator of the Arctic region, the polar bear has great camouflage and plenty of power. However, even these tools aren't always enough to find food, and if things get extreme enough, polar bears have been known to kill and eat cubs of their own species.

Of course, killing its own kind isn't a go-to strategy for a polar bear. The animal's main food source is fatty seals, which give the up to 1,700-pound predator more than enough energy to keep going. Problems arise when there are no seals available. Polar bears that aren't able to stalk seals on ice are left to survive on whatever they can scrounge up on land. This generally amounts to eggs, berries, and the occasional reindeer — which, in turn, simply isn't enough to keep the massive animals going. Landlocked polar bears tend to operate on a constant calorie deficit that costs them up to 2 pounds of body weight every day. 

During a prolonged period of such hunger, desperate times may call for desperate measures, and it's at this point that an adult polar bear might start viewing nearby cubs as a food source. Climate change and the ensuing loss of sea ice has increased such behavior, as has the disturbance from human activity in their stomping grounds.

A fish that carries its eggs and even babies in its mouth might be able to protect them, but you can't help but wondering what happens if the mommy fish accidentally swallows? Well, the cichlid fish Astatotilapia burtoni does indeed occasionally feast on its young ... but it's not by accident.

Astatotilapia burtoni lives in the shallow peripheral areas of the African Lake Tanganyika, and is also known as Burton's mouthbrooder for obvious reasons: After mating, the female will protect its fertilized eggs by carrying them in its mouth. It takes the eggs about two weeks to hatch, but even after that, the mother fish's mouth continues to act as a home base of sorts for the baby fish who are slowly learning to explore their watery environs. 

As you'd imagine, spending weeks as a mobile nursery isn't a particularly fun time for the female Burton's mouthbrooder. It's not just a matter of discomfort, either. The mother fish can't eat during this time frame, since its mouth is otherwise occupied. And given that fish breathe by taking water in their mouth and absorbing oxygen through their gills, even this basic necessity for survival may become an overwhelming task. In 2022, a Michigan State University study discovered that the vast majority of mouthbrooder mothers deal with the situation by eating some of their young. This way, the mother fish can retain its health during the arduous child-rearing period and go on to procreate more.

Chimpanzees are one thing, but learning that adorable capuchin monkeys also sometimes cannibalize their young seems like a step too far in the "What on Earth, primates?" direction. Yes, capuchin monkeys — the cute little guys like Marcel from "Friends" – also eat their babies sometimes. Fortunately, such acts are incredibly rare among them, as well as primates in general. When they do occur, they tend to be connected to early infant deaths ... or, as the following example shows, even the monkey equivalent of murder cases.  

Researchers encountered a textbook example of this behavior in 2019, when a long-observed capuchin group that resided in Costa Rica's Santa Rosa National Park consumed a 10-day-old that had fallen to the ground from the trees where the monkeys were hanging out. The baby's mother made multiple attempts to retrieve and carry it before the group determined that the infant was indeed dead. It wasn't until then that they started eating its body, with an older female that was related to the dead infant consuming the majority. Judging by the way a male monkey was promptly chased out of the pack after the infant's fall, the culprit was also quickly identified and punished. 

Jaguars look beautiful, but as is so often the case with wild animals, it would be a profoundly bad idea to pet one. These big cats are among the animals with the strongest bite force, and they like to hunt by biting their prey's skull to pieces. Oh, and they might also put their powerful jaws to use by ... eating baby jaguars. 

In a notorious case from 2019, an a jaguar mother in a Brazilian zoo ate (and possibly killed) its dead 2-year-old baby to the utter surprise of its caretakers and researchers. It's unknown just how common such behavior is because honestly, jaguars are incredibly hard to observe, and science still knows fairly little about their personal habits. However, they may share other big cats' tendency to eat their cubs in the wild. 

For big cats, killing younger members of the same species and eating them aren't necessarily connected. Male lions often kill cubs that are not related to them — not because of hunger but because they want to mate with the female lions and spread their own genes, which they can't do when the females are nursing cubs. On the other side of the equation, big cats who otherwise take good care of their cubs have been known to eat the babies if they die for unrelated reasons ... because at that point, they simply see the dead body as a source of nutrition.

Apart from colorful, poisonous little guys like the blue poison dart frog, it's easy to think that most frogs are just sort of there, hanging around in ponds and jumping about in search of insects to catch with their sticky tongues. The reality is considerably less idyllic and involves a hefty dose of cannibalism. Yep, several frog species eat not only each other, but also their own young. "It seems that frogs, if they are in the right place at the right time, will eat anything that moves," John Measey of the Centre for Invasion Biology at Stellenbosch University in South Africa said to Live Science.

From an infant cannibalism standpoint, this tendency to feast on anything that fits in their mouth plays out in several strange ways. For instance, African clawed frogs have been known to feed on both their own young and the tadpoles of the South African frog. The highly invasive cane toad has taken things even further by introducing infant-on-younger-infant cannibalism as an evolutionary trait: During times when populations get unsustainably big, the cane toad tadpoles will swim to younger hatchlings that aren't yet able to move and eat them. Apart from reducing the number of hatchlings that are able to mature into tadpoles themselves, this method of natural selection can cause hatchlings to develop far faster than usual in an attempt to avoid being devoured. 

Both types of alligators (American and Chinese) seem very bite-happy, and especially the massive jaws of the American alligator look ready to eat just about anything. This, unfortunately, can be very bad news for younger alligators who are still too small to fend off just about any threat ... especially adult gators. 

Even without their cannibalism-inclined elders, young gators already have plenty to worry about: Despite mother gators watching over their babies, up to 80% of young American alligators get eaten. Their predators include just about every species the adult alligators will eventually terrorize, from large fish and birds to mammalian predators. Researchers have also determined that in Florida, up to 7% of juvenile gators end up eaten by older members of their own species. These aren't just one-off incidents where an adult gator accidentally devours a baby one, either. Analyzing data from the early 1980s, a 2011 study with tagged gators found that one particular American alligator had as many as 14 tags from other alligators in its belly. 

The numbers from Florida, of course, aren't necessarily indicative of what's going on with alligator populations elsewhere. However, they do suggest that adult alligators are perfectly willing to supplement their diet with infant gators ... which, while unsavory, does actually go a long way toward managing the area's alligator population. 

Rats are present wherever human populations are, and sometimes, radical changes in our behavior manage to catch them completely off guard. When the COVID-19 pandemic hit the country, many rat populations soon found out that their food sources were severely limited. Since many stores, restaurants, and other sources of delicious food waste had suddenly shuttered their doors as people were isolating at home, rats all over America were soon deprived on the reliably replenishing sources of trash-based nutrition they had accustomed to relying on. This, of course, was a problem because they still needed to eat.  

Different rat populations handled things differently. Some took to the streets in large swarms to find food. Others invaded nearby rat populations, leading to brutal "rat wars." Many resorted to cannibalism ... and, yes, eating their young.  

In all fairness, none of this is the kind of behavior rats would necessarily indulge in if food is abundant. Instead, extreme behavior like rats eating their own pups is triggered by sheer desperation and lack of resources. "They're mammals just like you and I, and so when you're really, really hungry, you're not going to act the same — you're going to act very bad, usually," rodentologist Bobby Corrigan told NBC News. "So these rats are fighting with one another, now the adults are killing the young in the nest and cannibalizing the pups."  

The family life of a scorpion isn't what you'd call an emotional affair. The jury is out on whether female scorpions routinely cannibalize the males after mating as previously thought, but male scorpions still run the risk of getting eaten if they overstay their welcome after the deed is done. In fact, even assuming that both parties crawl away unscathed, there may still be cannibalism involved on the female's part. She just waits a little while longer and targets her offspring. 

You may have seen images of tiny infant scorpions riding on the mother scorpion's back. This happens because the babies are still very soft and squishy, so mother scorpion will act as their tour bus for some weeks, providing protection until their exoskeletons get a chance to harden a bit.  

Unfortunately, the luxury of this early-life ride comes with a potentially nasty catch. Sometimes, the mother scorpion isn't able to find enough food for herself while lugging all of her offspring around. In such cases, sheer hunger may cause the scorpion to view the (up to 100 or so) squishy little babies on her back as handy little protein packs ... and to act accordingly. 

Why did the chicken cross the road? For any amount of reasons, but at least one of them is to feast on chicken eggs. There are many things to pay attention to when it comes to keeping chickens. Classics like keeping foxes away from the coop are a given. Large-scale, process-defining issues like doing your share to lessen the ecological impact of chicken farming are an important thing to pay attention to. However, unless you're already familiar with chickens, there are also some absolute curve balls on the way, such as chickens potentially munching on their own eggs. 

The problem is common enough that numerous farm-themed websites have guides on how to prevent this behavior, as well as analysis about its reasons. Chickens might start experimenting on an egg-heavy diet if they get the chance to, say, peck an intact egg out of sheer curiosity. They might also come across a broken one and discover that it's a handy source of nutrition. Once the egg-eating behavior is learned, a particular chicken may very well become a repeat offender that can even spread the habit to the entire flock.

Tricks to keep chickens from eating eggs include providing them with a healthy diet, which prevents nutritional issues that might cause them to seek additional sustenance. Supplementary, eggshell-strengthening calcium and adequately spacey living conditions will also reduce the risk of accidental egg breakage that might prompt such behavior.