Well, okay, I will correct you.
Most reptiles do not sense prey by heat. Obviously a heat sensing organ would be useless to the vegetarian species and of no particular value to those feeding on cold-blooded prey like insects and frogs. It also wouldn't work at all under water, since currents would carry the thermal signal away. Hence, tortoises, terrapins, turtles, crocodiles, lizards, and most snakes all lack the ability to use heat perception to find food.
Only the pit vipers have thermoreceptors, organs that detect heat at a distance. These organs are the "pits" from which they get their name. The most familiar pit vipers are perhaps the rattlesnakes.
The majority of snakes hunt their prey by a combination of smell, "sound", and vision. Snakes sample the air by pulling air into the mouth where the Jacobsen's organ allows for improved olfaction. While they don't really have ears as such, so probably can't hear sound as we know it, snakes are very sensitive to vibrations in the ground and will use that sense to localise and track prey. Snakes have surprisingly good eyesight, and this is used to target the prey for the final strike.
Fooling captive snakes such as boas and garter snakes therefore relies on stimulating one or more of these sense. Wiggling dead food seductively or smearing it in the 'taste' of something they normally eat are the sorts of tricks used.
Cheers,
Neale
also when it comes to reptiles, i think that they only eat live foods because most (correct me if i'm wrong) if not all use heat receptors to sense prey, if it doesn't move, it doesn't kow it's there.
