Adult A. contortrix are usually not confused with the Cottonmouth, yet the juveniles of both species are very similar. Young A. contortrix lack the chocolate cheek stripe seen in A. piscivorus , instead having the a light tan area below the eye to the corner of the mouth. Living in leaf piles beneath trees, or alongside logs and stones in wooded forests, the Copperhead is able to elude predators because of its camouflage. This cryptic behavior also allows copperheads to strike at unsuspecting prey. The pale gray or olive-colored tail of the Copperhead is sometimes used to lure prey to within striking distance.
Prey includes rodents, birds, lizards, frogs and other amphibian species.
Being nocturnal during the hotter summer months, A. contortrix is active during the day only during the cooler spring and fall months. There is also evidence that copperheads may only give birth to young every other year. The distinctions between these are based on color variations, yet some of these variations have been shown to be variable within the range of a single subspecies. It is the smallest of the Texas subspecies. In A. c. contortrix , these bands are additionally constricted near their bases, and at times may not be as distinct from the background coloration as in the other subspecies.