The copperhead is the most common venomous snake in Kansas. It does not have a rattle on its tail. The copperhead prefers rocky, partly wooded slopes. Its color pattern makes it difficult to see among rocks and fallen leaves. The copperhead prefers to sit still to avoid being seen by predators. Copperheads feed on mice, small rats, lizards, and insects.

The racer is one of the fastest snakes in Kansas. It lives in open prairies and pastures. If surprised, it may thrash vigorously to attract the predator's attention, then quickly glide away. The racer is one of the few large snakes in Kansas that regularly eats insects. It also feeds on mice, birds, lizards, and other snakes. Young racers are pale gray or tan with brown blotches, similar to the young prairie kingsnake or great plains rat snake.

The timber rattlesnake is the largest venomous snake in Kansas. It may grow to more than 5 feet in length. It is found on rocky, wooded hillsides in eastern Kansas. The timber rattlesnake is shy and retiring. Often, it will not rattle when approached. The timber rattlesnake feeds on mice, rats, squirrels, and small rabbits. It is disappearing in many ares where it was once common in the eastern United States. The timber rattlesnake is a species in need of conservation in Kansas.