How Does a Snake's Body Work?

How a Snake See, Hears, Smells and Tastes

Snakes can't see or hear particularly well, though they do have some advantages. With an eye on each side of the head, snakes have a wider viewing range than humans. They can sense movements easily but can't focus well. Snakes don't have outer ear openings so their hearing is somewhat limited. Though a snake's tongue only has a few taste buds, it has a smelling organ. This organ, called Jacobson's organ, gives the snake a keen sense of smell. Jacobson's organ is two hollow sacs in the roof of the snake's mouth. The nerve endings in the sacs are sensitive to smells. A snake's tongue flicks out to pick up odors and pulls back to allow those odors to enter Jacobson's organ. Other snakes have something similar called a pit organ. Instead of scents, pit organs detect body heat.

How a Snake Eats

A snake's jaw is attached to the skull with muscles, ligaments and tendons to allow snake jaws to expand greatly. The upper and lower jaws are connected with the quadrate bone, but during eating, the lower jaw can dislocate itself to swallow larger meals. The meal is gradually pulled into the esophagus by working the lower jaw back and forth over the food while the teeth in the upper jaw hold it in place. If the meal is a live one, the snake uses venom injected into the animal through the snake's fangs to subdue the animal so it can be eaten. Other snakes will wrap themselves around their prey and kill it by crushing it. The food is drenched with saliva to ease its entrance into the snake. Once in the digestive tract, the food is crushed and broken down so nutrients can be removed. Snakes that eat large meals use a lot of energy to digest it. When this happens, a snake's internal organs shrink. The organs must build back up to their normal size before the snake can digest more food.

How a Snake Moves

Snakes can move in four different ways: serpentine, sidewinding, concertina and rectilinear. Because a snake's body is mostly made up of rib pairs connected to a backbone, snakes have a great deal of flexibility in their movements. Most snakes move in the serpentine way. The snake contracts its muscles, pushing its body side to side. The snake moves forward when its contractions are able to push against something like water or rocks. The resulting motion creates S curves. When a snake sidewinds, it actually pushes itself off the ground sideways. Concertina is a method snakes that climb use. The snake extends its head and find a place that its ventral scales can grip. Then it pulls its body up into a bunch, middle first making sure to get a good grip with the ventral scales before pulling up its tail. The rectilinear movement is the same way a caterpillar moves.

How a Snake Maintains Body Heat

Snakes are cold blooded. This means their body temperatures can change, depending on the environment. This is why many times you will see snakes stretched out in the open sun. They are trying to warm their bodies up.

How a Snake Sheds Its Skin

A snake has an elastic skin covered in scales made of keratin. When the skin begins to wear out, it is time for the snake to molt. The snake's outer layer of skin softens and begins separating from a new layer of skin that is developing. When the snake is ready to molt, it rubs its mouth against a hard surface until the outer layer begins to pull off the head. The snake continues crawling and scraping until all the skin is off, which can take as long as 2 weeks.

Resources

• World Book's Page on Snakes