The term “black snake” in North America often refers to several species, but the one most frequently associated with chicken coops is the Black Rat Snake, also known as the Eastern Rat Snake (Pantherophis obsoletus). These large, non-venomous constrictors are highly adaptable and frequently live near human structures, including barns, sheds, and poultry houses. This tendency to inhabit farm environments brings them into direct contact with chicken eggs, leading to the common question about their diet.
The Direct Answer: Identifying the Egg Eaters
The answer to whether black snakes eat chicken eggs is a definite yes, with the Black Rat Snake being the primary culprit in many regions. This species is so notorious for this habit that it earned the long-standing nickname “chicken snake” among farmers and homesteaders. Rat snakes are excellent climbers, allowing them to easily scale rough wood, brick, and even trees to access elevated nesting boxes or coops.
They are drawn to coops for two main reasons: the eggs and the rodents that the chicken feed attracts. Eggs represent a high-calorie, low-mobility meal that requires minimal effort to subdue. The presence of mice and rats, which are the snake’s preferred prey, also serves as an initial draw, with the eggs becoming an opportunistic and appealing secondary food source.
Once a rat snake locates a clutch of eggs, it may consume several at a time, depending on the snake’s size and the egg size. An adult chicken egg is a substantial meal, providing a significant nutritional boost for a snake that may only feed once every few weeks. Since they are non-venomous constrictors, their feeding strategy involves consuming prey whole, which applies directly to the ingestion of eggs.
How a Snake Consumes a Whole Egg
The ability of the rat snake to consume an object as large and spherical as a chicken egg is due to specific anatomical adaptations that allow extreme flexibility. Snakes lack a sternum, which allows their ribs to separate and flare out, creating room in the body cavity for large prey. Their lower jaws are not fused at the chin and are connected by highly elastic ligaments, permitting the mouth to open far wider than the snake’s head diameter.
The snake swallows the egg whole, using alternating movements of the jaw bones to walk the egg down the throat and into the esophagus. Once the egg is deep inside the body, the rat snake uses powerful muscle contractions to press the egg against its own vertebrae, crushing the shell. The rat snake typically either digests the crushed shell completely or passes the small, compressed fragments in its waste.
Protecting Your Flock and Eggs
Preventing access is the most effective strategy for protecting eggs and ensuring the safety of the snake. Since rat snakes can squeeze through surprisingly small openings, any gaps in the coop or run larger than one-half inch must be sealed. The best material for this exclusion is galvanized hardware cloth, ideally with a quarter-inch mesh size, which is too small for any snake to penetrate.
Securing the perimeter involves removing potential hiding spots near the coop, such as wood piles, debris, and overgrown vegetation. Snakes use this cover to approach the coop unseen, so maintaining a clear, short-cut grass border makes the area less appealing. Elevating nesting boxes off the ground can also make them harder to access, though rat snakes are accomplished climbers and may still find a way in.
Managing the rodent population is also an effective, indirect deterrent because snakes are often initially attracted by mice and rats. Storing feed in sealed, metal containers and using treadle feeders that limit spillage will reduce the food source for rodents. Black Rat Snakes are beneficial predators that control rodent populations, and non-lethal exclusion methods protect both your flock and the local ecosystem.