Pit Vipers can SEE heat radiation or the Infra Red Rays! Some aliens are portrayed with this special scary

ability in some Science Fiction movies.

Infra red rays are being emitted by all living things and are invisible to human eyes. Two pits (which give

its name to this snake) lie between the eye and nostril on each side of its face.

Each pit has ~ 15,000 heat sensitive cells. This snake can find the presence of, the size of and the

distance of even small animals , several meters away, in complete darkness.

Pythons has a similar but less sophisticated system with the pits around its lips.