Disturbance by humans and lack of suitable den sites appear to be the major limiting factors for rattlesnakes in Connecticut. In the past, some Connecticut towns had bounties on rattlesnakes, and many of the dens were repeatedly decimated. Once documented in over 20 towns in Connecticut, this snake is now limited to isolated populations in 10 towns. These pits are sensitive to radiant heat and help the snake detect warm-blooded prey in the darkness. Their sense of smell is highly developed.
Snakes flick their modified forked tongue in the air, collecting scent particles.
They have no ears but can detect vibrations in the ground to determine the size of passing animals, the animals' direction and distance from the snake. The rattle is an important warning device. Black rat snakes, milk snakes and others mimic a rattling noise by vibrating their tail in dry leaves. Rattlesnakes have 2 hollow fangs, which are connected to a venom gland and located in the front of the mouth. They are shed periodically and replaced.