Ruddy, a Western Diamond Back Rattlesnake in the Texas Reptile Zoo, comes like a cat or dog. Snakes do not have external ears and some research indicates snakes may pick up 200-300 Hz frequencies thru a vibrating bone on their skull.
Snakes have no visible ear, so they don't hear sounds as we do. But it's not quite right to say that snakes are deaf. They have vestiges of the apparatus for hearing inside their heads, and that setup is attached to their jaw bones, so they feel vibrations very well and may hear low-frequency airborne sounds