Snakes – General Characteristics

There are over 2,900 species of snakes and although each type may have its own individual needs, they all share common characteristics.

Snakes are said to be cold-blooded, but that’s not completely true. They are able to internally reproduce and regulate their body temperature, but just can’t do it effectively. This makes the snake ectothermic which means that they rely largely on external sources for heat, but not totally. To cool themselves, ectotherms simply move into a cooler area.

All snakes are meat eating carnivores and belong to the same group as lizards, turtles and crocodiles. They are found on every continent except Antarctica. Snakes do not have eyelids, or external ears, and their visions vary greatly. Some are almost blind, while others have excellent sight. The tree climbers see well and burrowing snakes have almost non-existent eyesight.

For those that have never touched a snake, it’s commonly believed that snakes are slimy. This misconception is thought to come from an association with worms. Snakes are covered in scales and have a smooth, dry textured feel to them.

Snakes shed their ‘skin’ once or twice a year through a process called moulting. The younger that are still growing may shed up to four times a year. Before moulting, a snake will stop eating and normally moves to a safe place. The skin will become dry and dull, with the eyes going cloudy, or blue-colored. The inner surface of the old outer skin liquefies which causes it to separate from the new skin. After a few days, the eyes clear and the snake will crawl out of its old skin by rubbing against rough surfaces. In many cases, the skin peels backward over the body from head to tail in one piece. This renewing of the skin is believed to be the reason snakes have been used as a symbol of healing and medicine.

Like any animal, snakes do have an odor. They don’t smell bad and most people don’t even notice unless their cages are not cleaned regularly.

Snakes are not aggressive and would rather slither away than have any confrontation with humans. Other than hunting food, snakes will normally only attack a person if it is grabbed, or unexpectedly disturbed.

A snake tracks prey by using its forked tongue to collect airborne particles that are ‘examined’ by sensory organs in the mouth. This fork in the tongue gives the snake a simultaneous sense of smell and taste. The tongue is always in motion, sampling chemicals in the air in search of prey, or predators.

The part of the snakes’ body contacting the ground is very sensitive to vibration and a snake can sense the faint vibrations of approaching animals. Some snakes, like pit vipers and pythons, have infrared-sensitive receptors in deep grooves between the nostril and eye, or pits on their upper lip just below the nostrils (common in pythons), which allow them to see radiated heat.

A snake has the most unique jaw of any animal. Snakes do not dislocate their jaws as commonly thought. They have a very flexible lower jaw that allows them to open their mouths wide enough to swallow their prey whole. Snakes have teeth, but they are made for grabbing and holding, not chewing.

The majority of snakes are solitary animals and only come together to breed. Some snakes lay eggs while others, like boas, give live birth. Snake parents do not rear their young and baby snakes are left alone to fend for themselves immediately after birth.

Snakes have four ways of moving around. The “concertina” method is when snakes bunch themselves up and then throw themselves forward. A “serpentine” motion is what most people think of when they think of snakes. The snake will push off a surface (rocks, trees, etc.) to get going and will then move in a wavy motion. “Sidewinding” is when the snake lifts the middle of its body up and then pushes it down, forcing the head to move forward. The “rectilinear” method is a slow, creeping, straight movement. The snake uses some of the wide scales on its belly to grip the ground while pushing forward with the others.