Can Snakes Yawn?
Yes, snakes can yawn.
This is possible because rather than a simple hinge formed at the junction of the skull and lower jaw, snakes feature another set of bones in the jaw joint. These bones allow the jaw to hinge at two points, instead of a single point as happens with other species.
On the other hand, their lower jaw is attached by ligaments; instead of moving as one piece, ligaments allow the two halves of the lower jaw to move independently.
So, even if some people mistakenly believe that snakes can dislocate their jaw, this is not correct: snakes are in fact biologically furnished to open their jaw widely. And there’s a good reason why nature designed snakes’ mouths to open wide: snakes have fangs but don’t have the kind of teeth that can chew, they are not equipped with molars or incisors…
Why do snakes yawn?
Contrary to popular beliefs, snakes do not yawn because they are tired. It’s not sleepiness. Yet yawning has still biological reasons. There are in fact four reasons that make snakes yawning:
1. To get ready to eat:
by yawing a snake realigns its jaw to prepare for a prey to pass into its throat.
Because of their flexible skulls snakes are infamous for their ability to swallow whole preys considerably larger than its head. Tales of pythons and anacondas eating large prey, even humans, abound.
The subject is rife with exaggeration: even if in some cases, snakes successfully ingest prey more massive than themselves, most prey represent a third or less of the snake’s body weight.
2. After eating, to force their jaw back into normal position:
Once the snake is done swallowing, it yawns to force its jaw back into normal position.
3. To get information about the environement:
by yawning, snakes pick up in the air information about their environment.
When a snake opens its mouth wide and flicks its tongue in and out, the tongue makes contact with the opening of the vomeronasal organ also known as the “Jacobson’s Organ”. This organ allows the snake to pick up and interpret environmental cues. When the scent is deciphered, the snake will know what type of prey is near.
4 .Sometimes, snakes yawn because they are feeling sick:
Snakes are exposed to bacterial and fungal infections coming from the preys they eat. If your pet snake is yawning it might be a sign of pneumonia or another respiratory disease.
While yawning, a snake with bacterial or viral pneumonia will commonly blow bubbles from its mouth and nose.
One thing you could do to prevent your snake pet to get sick this way is to train your snake to eat dead prey. While being hunted by the snake, a prey would naturally try to harm the snake by biting it.
Even a small mouse can bite and severely injure a pet snake by inducing a severe potentially life-threatening infection from the bite. Offering your pet snake dead prey is not just more humane for the prey but safer for your snake.
Snakes do not yawn because they are tired:
Even if humans do, snakes don´t. In fact different snake species yawn for different reasons.
For example fish yawn to clear the water from their gills -or in some cases, as a show of aggression- while dogs yawn may indicate anticipation or stress.
On the other hand, cats seem to yawn for the same reason humans do, even if some experts speculate that felines sometimes yawn as a means to communicate with humans.
The most scientifically backed theory about why humans yawn is brain temperature regulation. A 2014 study published in the journal Physiology & Behavior indicates that yawning has to do with cooling out the body. Clearly, snakes do not need to cool out cause they already are cool blood individuals.
What happens in the case of humans is that when our brain’s temperature gets too far outside of the norm, by inhaling air we can help cool it down. So we yawn. When we are tired, our brain is slowing down, causing its temperature to drop. When we are bored our brain isn’t feeling stimulated and starts to slow down, causing also a temperature drop. Last but not least, when we are seeing someone else yawn, as we’re in the same environment, we’re exposed to the same temperature. So we yawn because our bodies want to wake up. The motion does also help to stretch our lungs and their tissues, and allows our bodies to flex muscles and joints. It may also force blood toward our face and brain to increase alertness.
Humans are warm-blooded, so it makes sense yawning to cool down our blood when we’re too warm. But snakes are cold-blooded animals, so they would not yawn for this same reason.
More About Yawning Snakes
So, do snakes yawn? Definitely yes. When snakes yawn, it might mean many things but definitely not that they are tired.
Yet like humans, snakes have biological reasons to yawn: to get ready to eat, to force their jaw back into normal position after eating, and as an act of detection.
In the particular case of snakes, yawning might also mean they have got sick because of the exposure to infections coming from their preys.
Snakes do everything slowly, and even get sick slowly. Therefore, it can be very difficult for you to realize your pet snake is ill until the disease is advanced.
The signs that a sick snake displays will vary depending on the nature of its illness.
However, what you can do in order to minimize risks is to pay attention to the following signs: does your pet snake looks lethargic, less active, or is it yawning? It might mean is sick and should be examined by a veterinarian right away.