Obviously, snakes yawn because they're tired...right? Well, if you believe that, then I've got a bridge to sell you...in Brooklyn!
So if it's not sleepiness, then why DO snakes "yawn"? And are they actually even yawning at all? Read on to find out!
Why Snakes "Yawn"
One reason snakes 'yawn' is to prepare themselves for a hearty meal, especially when their prey is considerably larger than their head! Yawning helps snakes open their jaws incredibly—one might even say _impossibly_—wide. Contrary to popular beliefs, snakes do not unhinge their jaws. Rather, their lower jaw isn't attached by bone in the first place, nor is it even in one piece—it's separated in the middle and attached by ligaments, allowing one side to move independent from the other side. This allows the snake to move its food down into its body a little at a time, the entire digestion process taking sometimes several weeks!
There are other reasons for snake yawning or, as I like to call it, "mouth gaping." A more recently discovered reason for mouth gaping is that is allows them to pick up chemical cues from their environment like many mammals in the animal kingdom. On the roof of the snake's mouth is the vomeronasal organ also known as the "Jacobson's Organ." When a snake opens its mouth wide and flicks its tongue in and out, the tongue makes contact with the opening of this organ after the tongue is retracted. This allows the snake to pick up and interpret these environmental cues. The well-known flicking of a snake's tongue is actually the snake gathering scents from the air and passing the information to the vomeronasal organ. When the scent is deciphered, the snake will know what type of prey is near.
A Sign of Disease
Unfortunately, frequent yawning can also warrant concern because it can be a sign of disease. Snakes are susceptible to all types of bacterial and fungal infections due to the type of prey they devour. For example, an ingested mouse or rat containing host larvae may result in parasites migrating through the snakes tissues which can cause an infection. If your pet snake appears ill, it is always best to consult your vet, as disease-causing organisms can cause symptoms similar to other unrelated illnesses. You never want to second guess what is making your pet sick.Tests must be made and medications must be dosed properly based on the snake's body weight.
By Tom Matteo