Many interesting facts about snakes relate to their anatomy, such as the fact that they don't have eyelids and that they have internal rather than external ears. A snake’s body can have over 300 pairs of ribs, and its organs are placed sequentially to adapt to its tubular shape.
The sac around a snake's heart is both movable and mobile, and its heart has the ability to shift 11 1/2 times its length to accommodate the passage of food. Snakes are carnivorous and have the ability to smell prey with their tongues.
There are over 3,000 species of snakes, and they are found on every continent except Antarctica. Seven of the deadliest snakes are found in Australia. The world’s thickest snake is the anaconda, which can have a circumference of up to 44 inches. The world’s smallest snake is the thread snake, which is about 4 inches in length.
The black mamba is a particularly venomous snake. It has a bite that kills up to 95 percent of its victims, and it can travel at speeds of up to 12 miles per hour. Spitting cobras have venom in their bites that they can force through small channels in their fangs.