There are about 3,000 kinds of snakes. Here is information about the different functions of these cold-blooded animals' physical characteristics. One also learns how they live, how they give birth (most lay eggs, some give birth to live babies), and how they eat (they swallow their prey whole, sometimes while it is still alive). Knowing about snakes, from the most ordinary garden variety to the most exotic constrictors and poisonous snakes, is to admire and respect these extraordinary reptiles.