Animals that actually eat parts of their own bodies

Lizards

Lizards such as fat-tailed geckos, red-tailed skinks, grass lizards, green anoles, and leopard geckos can drop their tails when attacked to distract predators. After escaping, many of them eat the detached tail to recover lost fat, nutrients, and calcium. This behaviour is common among skinks and lizards and can account for up to 20% of their stored energy, particularly during food shortages or stress.​

Female African social spiders can sometimes allow themselves to be eaten by the young to ensure the brood’s survival (Image: Wikimedia Commons)

Spiders

In some spider species—such as the black lace-weaver, desert spider, and social Stegodyphus spiders—mothers sacrifice themselves for their offspring. After the eggs hatch, the spiderlings feed on the mother’s liquefied body, gaining vital protein that can make up about 30% of their early nutrition. Many spiders also chew off and consume injured or shed legs, recycling valuable nutrients such as proteins, minerals, and chitin rather than wasting them.​

Crustaceans

Autophagy, or eating one’s own body parts, is common among crustaceans such as crabs (e.g., hermit crabs), lobsters (Homarus spp.), and shrimp. As soon as they molt or shed their exoskeletons, these creatures start eating it to reclaim calcium and minerals, to recycle nutrients. In fact, there are also significant cases of cannibalism where these crustaceans attack and eat the soft bodies of fellow beings, as soon as they shed their hard exoskeleton.

Green tree frogs shed their skin periodically, often every couple of days, and then eat it (Image: pexels)

Frogs and Toads

Frogs are also fans of nutrient recycling via dermatophagy. In this context, frogs and toads, such as green treefrogs, routinely shed and eat their skin to recycle proteins, support skin microbiomes, and erase scent trails. According to some schools of thought, this behaviour may also potentially aid in self-immunisation against pathogens. These amphibians are also known to indulge in cannibalism. ​​

Snakes

This behaviour, scientifically termed ouroboros, is extremely rare in snakes, having been reported only in captive snakes to date. When these reptiles in captivity are extremely stressed, for example due to temperature, their brains stop functioning properly, and they mistake their own tails for potential prey and attack them. Similarly, some captive snakes, such as garter snakes, California kingsnakes, and corn snakes, may occasionally consume shed skin to obtain minor nutritional benefits and to reduce scent trails. ​​