Scientists found snake cannibalism in over 200 species, and it’s more common than you think

Cannibalism is one of those behaviors that instantly shocks us. It feels extreme, almost unnatural, something that should happen only in desperate or unusual situations. For years, that’s how scientists also thought about cannibalism in snakes: rare, accidental, and worth noting only when something had clearly gone wrong.

That view is changing fast.

A large scientific review recently showed that cannibalism among snakes isn’t an exception at all. It’s common, widespread, and surprisingly ordinary. According to the study, documented cases now span more than 200 snake species, cutting across habitats, climates, and snake families.


In other words, this behavior isn’t a freak occurrence. It’s part of how many snakes survive.

What the research actually found

The shift comes from a comprehensive analysis titled Cannibalism among snakes is far more widespread than previously thought. Researchers pulled together decades of observations from scientific papers, field notes, museum records, and wildlife reports.

Instead of focusing on a few dramatic incidents, the review looked for patterns. And the pattern was clear: snakes eating other snakes happens far more often than scientists once assumed.

The behavior occurred in grasslands, forests, wetlands, deserts, and even near human settlements. It wasn’t limited to aggressive species or unusual conditions. In many cases, it seemed almost routine.

Why do snakes eat other snakes?

From a human perspective, cannibalism feels disturbing. From a snake’s perspective, it can be practical.

Snakes are opportunistic feeders. If something is the right size, provides enough energy, and doesn’t fight back too hard, it can become food, even if it happens to be another snake. The review explains that cannibalism often occurs when food is scarce, habitats overlap, or competition becomes intense.

Earlier research helps explain this logic. A classic ecological study by biologist Gary Polis, published in Annual Review of Ecology and Systematics, described cannibalism as a survival strategy in many animal groups, especially predators. The behavior isn’t about aggression; it’s about efficiency.

For snakes, another snake is familiar prey. Their bodies are already adapted to swallowing long, flexible animals. In some situations, it’s simply the easiest option.

Size matters more than species

One of the clearest patterns across studies is the size effect. Larger snakes are far more likely to eat smaller ones, particularly juveniles.

Research on king snakes, published in journals like Herpetologica, has shown that some species regularly prey on other snakes, including members of their own species. These snakes are even venom-resistant, making them a low-risk meal for other snakes.

Timing also plays a role. Cannibalism becomes more common during breeding seasons, when many snakes gather in the same areas and competition peaks. In these moments, opportunity matters more than species boundaries.

Why did it go unnoticed for so long?

If cannibalism is so common, why did it take decades to recognize?

Snakes are notoriously hard to observe. Many are nocturnal, secretive, and quick. Cannibalism events happen fast and often leave little evidence behind. Earlier studies also tended to categorize snake diets broadly—rodents, birds, amphibians—without paying close attention to snake-on-snake interactions.

The new review argues that cannibalism was always there. Scientists weren’t looking for it as a meaningful pattern.

Rethinking “abnormal” animal behavior

This research fits into a broader rethink happening across animal science. Behaviors once labelled as abnormal are increasingly understood as flexible responses to environmental pressures.

Studies on reptiles published in journals such as Behavioral Ecology suggest that cannibalism can help regulate populations, reduce competition, and even stabilize ecosystems under stress.

Seen this way, snake cannibalism isn’t a breakdown of nature’s rules. It’s one of them.

Why this matters beyond snakes

Understanding how animals really behave matters more than it might seem. As habitats shrink and food sources change, behaviors that once seemed rare may become more common.

The researchers behind Cannibalism among snakes note that recognizing these patterns helps scientists predict how species respond to stress—and reminds us that nature doesn’t follow human moral instincts.

A behavior hiding in plain sight

For a long time, snake cannibalism was treated as a shocking anomaly. The evidence now suggests it was hiding in plain sight all along.

Once scientists stepped back and looked at the full picture, a different story emerged—one in which survival, not shock value, explains what’s really happening.