Snakes: The nocturnal hunter
Rattle snakes are nocturnal hunters and use a pit located between the nostril and the eye to detect infra-red radiation. The detection of heat given by a small mammal is also directional, and therefore it is able to attack its prey even in pitch darkness. Being ectothermic, food requirements are, however, small and therefore less time is spent foraging than the equivalent sized endothermicmammal. This ensures their success even in the most inhospitably dry regions of the world.