Copperhead snakes are found from New England to northern Mexico, and they are venomous and can be aggressive. However, their venom is mild and rarely kills adult humans.
Copperheads have pits in their heads that sense heat. This sensory organ allows them to find prey more efficiently. They are about 3 feet long and females tend to be bigger than males, though males have longer tails. Females have been known to give birth parthenogenetically.
The snake gets its name from its copper-colored head, and its body is patterned with chestnut or darker brown hour-glass-shaped blotches against a lighter background. Young copperheads are gray, and their tails are bright green or yellow.
Copperheads are somewhat thick-bodied snakes with keeled scales. They have orange or red-brown eyes, and their pupils are vertical slits that resemble those of cats. They thrive in a variety of habitats, including the suburbs.
Copperheads tolerate the presence of other snakes, including rattlesnakes, and often den up during the winter. They are more likely to be seen in the day in the cooler fall and spring months, but are active at night during the summer, especially after rains. They are able to climb trees and can even swim, and prefer a diet of rodents.