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LOOK MA, NO HANDS!

It is immediately obvious that SNAKES have no hands or feet! As animals go, this is very strange, but we have come to just expect it in the snake world. Have you ever stopped to think what it would be like to have to eat, get around, and do all the daily living things without any hands or feet?

Snakes have learned to do this quite effectively! They have several methods of "walking" so that each crawl technique is useful on a particular type of surface. If one way doesn't work very well, they will just try another until they get the movement desired. Some snakes "ripple" along by using the hard plates on their belly scales to grip, dig, and hold on to achieve their movement. The snake appears to be in a straight line while doing this with very slow forward motion as this approach is like a "ladder in reverse", moving the snake along when each scale is picked up and put down for the next grip.

Sometimes the snake uses a motion referred to as "serpentine" where curls or curves of the main body length push off of surface obstacles to propel the snake along at a good speed. This method is how the snake swims also, and is the most often observed technique we see when one crosses the road ahead of us to get out of the way. They always look like they are moving so much faster than they really are due to the illusion of speed created in the curving motions themselves. This is truly the snake crawl.

Another method used to move along is the "concertina" motion where the snake looks like a toy that contracts and retracts like an accordion. The propelling motion is gained by anchoring the rear section and shoving the forward part of the body ahead. Smooth surfaces usually find the snake using this method and it does work well as he bunches himself up and stretches forward, then repeats this movement again and again to get where he intends. This approach looks like a caterpillar inch worm on its side!

Sidewinders have an especially interesting movement! They have adapted to a crawl that is very impressive and move quite fast! Loose hot sand and soil conditions make this method a necessity.

Feeding is quite another problem! No hands means that the snake must grasp its prey and eat using only the mouth and a few teeth to get it all done - every day! This is a very impressive performance when you think about it and the snake has to have several adaptations to pull it off.

The teeth must first grip the prey. These are usually aimed at a backward angle in the mouth so that a struggling victim simply digs in deeper with each squirm. Some snakes have already constricted the prey and are holding it all wrapped up to prevent escape. The special tongue comes into play in that the snake must know how the prey is positioned before trying to swallow it. The majority of time, the snake swallows its prey head first after examining it closely with the exploring tongue. By swallowing something head first, the limbs of the prey fold down easier to make for smooth swallowing. Also, a head grasp without release tends to prevent injury to the snake from a dying, flailing prey which may also have some impressive defense system like sharp teeth.

While swallowing, the snake must continue to breathe so it has a hardened tube airway which extends beyond the throat. This supports breathing while swallowing a tasty morsel that may take up the entire mouth and throat area while passing through. This is much like breathing through a straw when we are submerged underwater without being able to otherwise breathe.

Additionally, the snake has very flexible jaw muscles and the lower jaws are hinged to the skull such that they can actually become temporarily dislocated while swallowing a large prey so that more room is created for the difficult but critical act of swallowing.

Finally, the snake has to have very powerful muscles along its sides to promote the process of "crawling" over the prey during the swallowing process. This is a slow and tedious way of pushing the head and open mouth over the victim, while pulling the prey with other muscles on down into the esophagus. All of the swallowing action systems must work closely in concert to make it happen. If all of this does not work out correctly for the snake, there is potential for injury or the discharge of hard to acquire food without any benefits at all.

As we might imagine, with this much difficulty in eating, the snake does not have a rapid digestive system. Some may go for weeks or months before facing this severe chore again! They do not chew their food so it does go down all in one piece which takes longer to break it down for the body's uses. Snakes are very vulnerable while eating as they have most of their defensive systems also tied up for the swallowing task.

Without feet or hands, the task of daily living can be a real task indeed! Snakes do very well with their specialized adaptations and are interesting to watch as they cope with such essentials as moving about and feeding themselves. Observing a snake as it routinely goes through these life skills adds a whole new meaning to the light little phrase we sometimes hear - 'look Ma, no hands'!

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