GENERAL EXTERNAL ANATOMY

The cross-section of snakes can vary from circular to trian­gular to ovoid, depending on the habitat. The belly is always slightly flattened to aid locomotion. The single ventral scales are called “gastropeges” and the scales caudal to the vent are simply called “subcaudal scales”. Arboreal snakes like constrictors have quite a prehensile tail.

Most snakes use color to camouflage themselves or to give warning signals. Snakes that live among foliage are often green whereas desert species are often yellow to red to match the sand. The venomous coral snakes (Micrurus species) have vivid bands of color to warn prey. “False” coral snakes such as the Milksnake (Lampropeltis triangulum) use the same mimicry to keep prey away, even though they are not venomous.