Campbell's Milk Snake
Part of the Lizards and Snakes: Alive! exhibition.
Beautiful . . . but deadly? Not! This harmless snake stays safe by wearing colored bands, imitating its venomous neighbor, the Coral Snake.
Coloration
Can you tell the harmless Milk Snake from its highly venomous neighbor, the Coral Snake? Don't count on it. The differences in band pattern can be slight, and a mistake could be fatal.
The Milk Snake may avoid being eaten by looking "bad," even though it isn't. The strategy, which scientists call Batesian mimicry, after a famous naturalist, is widespread in nature. The venomous snake copied by the Milk Snake on display--its "model"--is this Coral Snake, Micrurus laticollaris. If the band pattern on the model species varies from place to place, the mimic varies, too.
Mouth
People used to think these snakes sucked milk from cows' udders--which is where they got their name. The misunderstanding may have arisen because mice are among milk snakes' favorite food-and dairy barns can be full of mice.
Surface
The glossy, smooth scales on this snake inspired part of its scientific name. Lampropeltis means "shiny shield."
Meet the Family
Milk Snakes belong to a huge group, Colubridae, with a dizzying diversity of shapes and lifestyles. Some race along the ground. Some glide through the air. Some swim. Some eat snails and some eat only the internal organs of living amphibians. Most of the group is harmless, but some members--the Boomslang, for instance--can be deadly to humans. The earliest known fossil of the group, from western North America, dates to about 20 million years ago.
Eastern Hognose Snake (Heterodon platirhinos)
Toads are this eastern North American snake's favorite meal. The toads inflate themselves to avoid being eaten but are punctured by the snake's enlarged rear teeth and killed with venom. To escape being eaten themselves, hognose snakes hiss and hood like cobras. If that fails, they roll over and lie motionless, as if dead.
Fast Facts
NAME: Campbell's Milk Snake; Lampropeltis triangulum campbelli
SIZE: 75 to 90 centimeters (30 to 36 inches)
RANGE: Parts of Puebla, Morelos and Oaxaca, Mexico
DIET: Small vertebrates