Eli5: How do snakes consume things way larger than their mouths?


I watched an infamous video of a snake engulfing a whole egg. It didn’t bite it down or anything, it just extended its mouth like an elastic band. You can see the egg travel down the snake. How does this process not hurt it?

In: 10

Snakes are able to dislocate their jaws in order to eat food larger than their mouth would normally be able to open. Since snakes are essentially just a ribcage and a tube of muscle their bodies can stretch to accommodate the larger food.

On top of all that fun evolutionary perks they have a breathing tube in their mouth that lets them continue to breathe during the lengthy swallowing process.

Contrary to popular belief, snakes do not dislocate their jaws.

Snake skulls are not a single mass of bone, but rather many bones connected with elastic ligaments. Allowing their skull parts to move independently.

The bottom jaws are not connected in the front like ours (snakes have no chins, so no folding towels for them), in place of a bony chin, they have one of the aforementioned ligaments. This allowed them to stretch their mouth over very large prey.

Their bodies are similarly stretchy, and the ribs can expand to hold a big meal.

Tl;dr: Snake skeletons are made of lots of little pieces connected with stretchy ligaments.

If you look at a snake jaw you’ll see that they’re bottom jaws aren’t fused together in the middle like ours are! That combined with they’re very stretchy skin allows them to open their mouths very wide. They also have a special tube in their mouths that they can breath out of when prey takes up their whole throat. Snakes are basically just advanced scaley socks, just like how a sock returns to it’s original size after you stretch it, a snake will to. Please don’t go stretching snake though :>

My daughter has a corn snake – their heads are very stretchy when they consume their food. It’s interesting to watch how their heads flatten out and stretch to swallow a mouse.

Snake jaws are very different to ours. [Look at this picture.](https://v.etsystatic.com/video/upload/q_auto/Python_skull_1_edd5vl.jpg)

See how the lower jaw is split into two pieces? They don’t have a chin.

They can stretch those two ‘arms’ of their lower jaw quite wide apart, as well as twist them at strange angles. This helps them fit things down their throat that look like they should be too wide.

This is quite obvious in videos that [show snakes yawning](https://www.youtube.com/watch?v=BV4qPpKRpk0). (Trivia; snakes often ‘yawn’ after eating to re-align their jaws and generally stretch out their mouth and put it back to normal after eating something big.)

A common urban myth is that snakes “dislocate” their jaw to eat. This is both wrong and also kind of silly.

Once the food is inside the snake, it probably does feel a bit tight and full, like we do after we eat a big meal. But it doesn’t hurt the snake any more than having a full bulging belly hurts us – it just tends to look a bit more extreme on a snake because they’re just… all body, no limbs.