Snakes do eat other snakes, a behavior observed in many species across the globe. The practice of a snake consuming another serpent is broadly termed ophiophagy, derived from the Greek words ophis (snake) and phagein (to eat). For some snakes, ophiophagy is a significant dietary component, while for others, it is an opportunistic meal. This phenomenon occurs between different species, which is the most common form, and sometimes even within the same species.
Defining Ophiophagy
Ophiophagy refers to the predation of a snake upon any other snake species, regardless of whether the prey is venomous or non-venomous. This differs fundamentally from intraspecific cannibalism, which is the consumption of an individual by a member of its own species. While many snakes will engage in ophiophagy if the opportunity arises, only a select group has evolved to make it a primary part of their diet.
The elongated and limbless body of a snake makes it an efficient food source, offering a high mass of nutrition relative to its size. The main limiting factor in any predation event is the snake’s gape. The tubular shape of the prey allows the predator to consume a meal that is exceptionally long, maximizing caloric intake compared to bulkier prey like rodents.
Specialized Ophiophagous Species
Certain species have evolved highly specialized biological traits to facilitate a diet centered on other snakes. The King Cobra (Ophiophagus hannah), whose scientific name literally translates to “snake-eater,” is the most famous example. Adult specimens almost exclusively prey on other serpents, using potent neurotoxic venom to quickly subdue their elongated prey, including other venomous species like kraits.
North American King Snakes (Lampropeltis) are similarly specialized, using powerful constriction to kill their prey, which often includes venomous rattlesnakes. These constrictors possess a remarkable physiological resistance to the neurotoxic and hemotoxic venoms of the pit vipers they hunt. This genetic adaptation enables them to survive a defensive bite from their dangerous meals.
In South America, the Mussurana snake (Clelia clelia) also exhibits this unique adaptation. It possesses antihemorrhagic and antineurotoxic antibodies in its blood serum that neutralize the effects of venom from prey like the highly dangerous pit vipers of the region.
Ecological Reasons for Predation
The decision for a snake to consume another snake is often driven by environmental pressures and survival economics. One of the primary ecological triggers is resource scarcity in the local habitat. When typical prey like rodents, birds, or lizards become sparse, snakes may turn to other serpents as an opportunistic food source to maintain energy balance. This is especially true for generalist predators whose diet is not strictly limited to ophiophagy but are simply seeking the most available meal.
Intraspecific predation, or cannibalism, can also be a function of territoriality and competition within a shared environment. By consuming a smaller member of their own species, a snake effectively eliminates a competitor for food, mates, and shelter. Observations of male-male combat in some species, such as African cobras, suggest that this aggressive interaction can sometimes escalate to a predatory event. The high energy yield of an elongated prey item, combined with the removal of a local rival, makes the act a double benefit for the predator.