Sneaky Snake Facts

We all know that snakes are sneaky, but not everyone appreciates just how fascinating these slippery slitherers and other venomous creepy crawlies really are! This week, we’re kicking off a series in which we answer some of the most common questions people ask about snakes and other venomous critters. Strap in for some freaky facts!

Sneaky Snake Facts Volume 1

Garter snake

The long, forked tongue of a garter snake (Thamnophis sp.). Da Vinci Science Center (DSC) CC2.

Why do snakes poke out their tongue?

You may have noticed that snakes poke out their tongues a lot, especially when they are on the move. This is because they use their tongues to “smell” the air, which helps them navigate. This is called chemoreception, which literally means the receiving (reception) of chemicals (chemo). Airborne chemicals stick to the snake’s tongue when it is poking out, and the snake can identify the particles thanks to a special organ called the vomeronasal (or Jacobson’s) organ.

Jacobson's organ

The vomeronasal (or Jacobson’s organ) allows snakes to detect airborne chemicals, in a similar way to how we smell. Fred the Oyster CC4.

The vomeronasal organ is located in the roof of a snake’s mouth, and there are two small entry holes that lead to it – like nostrils, but on the inside of the mouth. Once the snake has waved its forked tongue around enough to get a good coating of chemicals, it brings the tongue back into the mouth and presses the tips of its forks against the organ – one fork tip in each hole. This sends a signal to the snake’s brain, telling it what the “smell” is. And if the signal is stronger on one tip of the tongue fork than the other, it tells the snake which direction that smell is coming from. This is how snakes are able to find hidden prey. If you want to know how snakes hiss, you can find out here!

Green tree python

Snakes, such as this green tree python (Morelia viridis), are so flexible that it may seem as though they don’t have any bones – but they do! David441491 CC2.

Do snakes have bones?

As snakes are so flexible, it may be tempting to think that snakes have no bones. However, snakes do indeed have bones. In fact, they have hundreds – even more than us humans.

Animals can be classed as either invertebrates (animals with no backbone) or vertebrates (animals with a backbone). Invertebrates include animals like jellyfish, squid, spiders, and insects. Their bodies may be very soft and squishy, like a worm, or they may have an exoskeleton (a hardened outer shell, such as that of a crab, beetle, or scorpion).

Snakes belong to the vertebrates, along with all other reptiles and amphibians, mammals, birds, and fish. All these animals have an inner skeleton.

Bones give structure and strength to bodies. Muscles are attached to bones, and this enables us to move as our muscles contract. Snakes need lots of bones so that they can be both strong and flexible. They have a special skull (more on this later!) and they have a very long spine, made up of hundreds of vertebrae (the bones that make up our backbone). They also have hundreds of ribs, almost the whole way down their body, to protect their organs. Some snakes catch and kill their prey by constriction. This means they constrict (tighten) their strong, muscular body around the animal they have caught and squeeze it to death, with the help of their bones. These snakes are super strong! Other snakes catch and kill their prey using venom. We will be talking all about venom in a future blog, so keep an eye out!

Snake skeleton

The skeleton of this Gaboon viper (Bitis gabonica) is mostly composed of hundreds of vertebrae and ribs. Stefan3345 CC4.

How do snakes eat such big things?

So, once a snake has caught its prey, how does it actually swallow something so much bigger than its head? To answer this question, first we will look at the skull structure of a typical vertebrate.

Polar bear skull

A polar bear’s sturdy skull helps make its bite so powerful. WitmerLab at Ohio University CC4.

Most animals have skulls that are similar in structure to this polar bear’s skull (shown above). These skulls are made up of two main parts: the cranium (brain case) and the mandible (lower jaw). There is also the maxilla (upper jaw), but in most animals it is fused to the underside of the cranium to form one large, strong structure. The cranium and the mandibular bones lock into place and are held together by strong ligaments. Having only two main parts to a skull ensures that it is very strong and sturdy. This is important for all the biting and chewing that we do. However, it also restricts movement, and this means that we can’t open our mouths very wide. Check out this interactive website to compare the skulls of lots of different animals.

Snakes, however, have a very unique skull that is made up of many separate bones. Both the upper and lower jaws are split into two parts each (left side and right side), and the cranium is also separate. The bones are held together by flexible ligaments, but they do not lock into place in the way that most other animals’ skulls do. This makes the snake’s skull incredibly flexible, and the jaw is able to stretch widely in multiple directions.

Boa skull

The skull of this tree boa is made of many unfused bones that are held together by tissue and ligaments. WitmerLab at Ohio University CC4.

Snakes are even able to move the left and the right side of the jaw independently. By moving one side of the jaw forward as the other side grips the food, they are able to slowly pull the food further into their mouth. This is how they are able to swallow such large prey whole – and using no hands!

Rock python swallowing antelope A big meal for this African rock python. alex_griffiths CC2

This week, we have learnt a bit about how snakes find, catch, and swallow their prey. Next time, we will find out what happens to their bodies once they have swallowed something so big! We will also talk about another predation strategy – venom.

If you have a burning question that you want us to answer in our next blog, feel free to drop us an email.

Thanks for reading and don't forget to check back for more sneaky snake facts and other information about venomous critters!

- Bianca op den Brouw

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Bianca op den Brouw