Snakes!

Class: Reptillia

Order: Squamata

Suborder: Serpentes (2,389 species)

Jump to a section:
Introduction
Conservation
Common Myths Dispelled
Natural History
Snake Senses
How Do Snakes Move?
Feeding Habits
Venomous Snake Bites
Links

Introduction
It is no secret that people have long feared snakes, probably since the beginning of time. Their slithering appearance has caused them to be misunderstood and poorly studied in the past. Fear of snakes, which is a learned behavior, is exasperated by folk tales, media misrepresentation, and so forth. Even though fear may be a component of our feelings toward snakes, we are also very curious about them. Snakes are fascinating animals, and they play an important role in our landscapes.

Conservation
Please don't kill snakes! Seeing a snake is not reason enough to kill one. Most snakes are more afraid of you than you are of them. Do not bother them. Just move away if you happen to come across one. Most of the snakes that you will run into are perfectly harmless. They couldn't hurt you even if they tried! Venomous snakes, on the other hand, can actually control the amount of venom that is injected when they bite. It is possible for them not to inject venom every time they bite. Remember that snakes are here for a reason -- they serve an important role as both predator and prey in complex food chains. So, the next time you see one, admire the snake from a distance only, and leave the snake alone.

Common Myths Dispelled

• Snakes are not slimy! People have slimy skin, not snakes. Although myths represent snakes as slimy, they have very dry skin. They don't even have mucous glands! Their scales aid in locomotion and prevent the snake from drying out.
• Snakes have a backbone! Snakes have backbones, just like people. Their skeletal structure is composed of hundreds of vertebrae, with a pair of ribs to go along with each.
• Snakes do not move very fast! Although they appear to move quickly, they are probably going no faster than 5 miles per hour, depending on the species.

Natural History
Because snakes are cold-blooded, they have to rely on their surroundings to control their body temperatures. Their cold-blooded nature is the reason that a large number of snake species are found near the equator and smaller numbers of species are found as you near the north or south poles.

Snakes are either oviparous (egg-layers), or ovoviviparous (live-bearers). The egg-layers have a shorter pregnancy, but live-bearers are able to move their developing babies to warm areas.

Snakes shed their outer layer of skin several times a year. Before shedding takes place, a liquid is secreted between the old layer of skin and the new one beneath it. Snakes are not able to see well at this time and can become irritable until their eyes clear up. After shedding, their skin will be shiny and bright. Each time a rattlesnake sheds their skin, a new segment is added to the base of the tail. So, you cannot tell the age of a rattlesnake by the number of segments on the rattle, since they shed more than once a year, and segments can break off.

Snake Senses
Snakes lack limbs, eyelids and external ear openings. Their sight is not very good, but they do have a wide field of view, and can easily detect movement. Their hearing is also poor, but can hear low-frequency sounds very well.

Why are snakes always flicking their tongues? To pick up chemical signals from their surroundings! The chemical molecules that they collect with their tongue are placed inside their mouth and then inserted into the Jacobson's organ. The Jacobson's organ analyzes the information, and tells the snake about the surroundings.

Pit vipers and most boas and pythons have a pair of large pits between the eyes and nostrils, which are very sensitive to temperature. By comparing the messages received on the right and left sides, they are able to tell exactly where their warm-blooded prey is.

How Do Snakes Move?
There are four types of motion that snakes use to get around. Which one is used depends on the type of snake, their habitat, and their muscular design.

• Rectilinear locomotion (moving in a straight line) uses the ventral, or belly, scales.
• Lateral undulatory locomotion (s-shaped movement) involves the dorsal or side scales
• Sidewinding throws head sideways, then body catches up
• Concertina (usually with a prehensile tail) accordion like motion

Feeding Habits
All snakes are carnivores. Some snakes eat frogs, other snakes, fish, or snails. Many snakes eat rodents, so keep them in your backyards!

The jaws of snakes are specialized to help them eat large prey. Their upper and lower jaws can move independently of one another. When swallowing prey, the two halves of the lower jaw move out of their sockets. Their teeth are pointed inward, which helps them to move the prey into their bellies. When they are finished, snakes yawn to put the jawbones back into place.

Venomous Snake Bites
Snake bites are not a common occurence. However, it's not a bad idea to take a few precautions. Always wear hiking boots, long pants, and stay on marked trails. If you should come across a snake, keep your distance. Pit vipers, venomous snakes, can be distinguished from other snakes by their head, which is triangular shaped.

If you are bitten, disregard everything that you've seen in movies about snake bites!

You should NOT:

• suck the venom out with your mouth
• apply ice to the affected area
• cut the area that was bitten to relieve pressure
• take alcohol or other drugs

You SHOULD:

• move away from the snake
• remain calm. I know, it sounds hard, but it may actually save your life.

Links