Snake Identification Key to Rodent Control

Five snake breeds that you may want to keep around.

Adult black rat snake

This black rat snake will help keep the rodent numbers down around the farm.

University of Georgia

Content Tools

As you quickly learn growing up on a farm, particularly next to a rock quarry as I did, not all snakes are poisonous. And, even the poisonous species are not completely bad; they often, like their nonvenomous counterparts, serve the welcomed purpose of controlling rodent populations.

The first nonvenomous species that comes to mind, which my brothers and I saw the most, is the black snake; we probably saw the black rat snake (Elaphe obsoleta). Black snakes chiefly prey on rats and mice, but they are also known to feed on chipmunks, other snakes, squirrels, birds and bird eggs. They are a constrictor, so they suffocate their prey before eating it. These snakes can be long, sometimes as lengthy as 8 feet. Black snakes are excellent climbers and largely arboreal.

Bullsnakes are another variety that we found around our farm. They will prey on other snakes, especially the young, but they primarily go after mice, rats, rabbits, squirrels and birds. They can be up to 8 feet long, and when threatened, a bullsnake will try to flatten its head into a more triangular, rattlesnake-like shape and beat its tail against surrounding foliage to make an imitative rattle. It is often this threatening tactic that is often a bullsnake’s undoing, since many people mistake it for a rattler and kill it. Bullsnakes have at least some immunity to poisonous species.

Another of the nonpoisonous snakes is the ribbon snake. This member of the garter snake genus is docile and commonly found as a pet. Their diet consists of worms, slugs, minnows, insects and small mice. They are relatively small, with size ranging from 1½ feet to 3 feet in length.

The milk snake is a member of the king snake family, and another of the nonpoisonous snakes that removes rodents around the barnyard. One myth is that the milk snake sucks milk out of cow udders, but this is just that, a myth. Milk snakes are not anatomically equipped for such a venture. The myth comes from their propensity to hang around barns, and therefore milk cows, because barns are usually cooler in temperature and harbor numerous rodents. Milk snakes feed mainly on rats, mice, squirrels, beavers, eggs, birds, reptiles, amphibians and invertebrates. Milk snakes, like some other snakes that aren’t poisonous, eat other snakes and have at least some immunity to poisonous snakes like the rattler.

Lastly, racer snakes are a breed of snake that captured my imagination at a young age. My mother often told the story about how, when she was young, a blue racer chased her across the yard from a field where my grandpa was bush-hogging, if my memory serves. Racers have a top speed of about 4 miles per hour, or an adult human’s brisk walk. When approached by a predator, the racer will flee to a burrow, rock crevice or thick vegetation.

Adults are uniformly black, blue, brown or greenish on top, and white, yellow or dark gray below. They range in length from 3 to 7 feet and eat large insects, frogs, lizards, other snakes, small rodents and birds.