Do Chameleons Yawn? {Yawning, Jawing, Gaping & Shaking Explained}

My chameleon is not tired. He is not scared. Then why is he yawning? Do chameleons yawn?

During my research and conversations with reptile community members and veterinarians, I found out many explanations.

In this article, you will find out all the reasons why chameleons opens their mouths and if it’s actually yawning.

Do Chameleons Yawn?

Your chameleon’s mouth opens wide and you equate it to a similar response in humans where we yawn for more oxygen when we’re tired. This is not the case for these reptile lizards.

The yawning you are seeing is more associated with gaping of the mouth as a defense mechanism against predators, behavioral changes and usually signifies that they feel threatened or wish to warn others to back off.

More details and explanations will follow in this article.

Why Chameleons Open Mouths

Yawning is not happening, but it sure looks like it. Let’s call the mouth opening of a chameleons one of three things for now:

  • Jawing
  • Gaping
  • Expelling

Jawing is when a chameleon may try to intimidate other species, predators or threats. If a chameleon is not used to you as a handler or someone else has entered their field of vision, they may jaw at them by opening their mouths.

Gaping of the mouth is similar and usually means they will open as wide as possible and possibly coupled with hissing, puffing up their bodies or turning to a darker color.

The final reason why their mouth is open could be due to expelling because of the excess heat from basking or direct sunlight. When they open their mouths, they are actually allowing hot air to release or expel.

Why Does a Chameleon Puff Out?

Chameleons are not the strongest, quickest or most fearsome animals in their habitat. They need to use all of their defense mechanisms, if they wish to remain solitary, territorial and forceful in their intention to warn others to back off.

They obviously have their most notable response which is to change color, but what if their camouflage doesn’t work and they are spotted?

They can used their speed which can top out around 21 miles per hour or they can stand firm and look bigger. This is when a chameleon puffs themselves out. Their bodies look larger, their jaw line overlaps on their neck and they may couple that with hissing sounds.

Overall, when a chameleon that is fearful, they need to hide it with the following tools to make sure they are not going to be caught, eaten or hurt:

  • Camouflage
  • Speed
  • Darker or brightening of the colors
  • Hissing
  • Jawing, gaping their mouths open
  • Puffing up their bodies
YouTube video

My Chameleons Keeps Shaking Head

My chameleon looks like he is yawning, but he is not tired. This reptile companion of mine is trying to tell me something when he is shaking his head. He doesn’t seem fearful or threatened.

Usually when they feel a threat or perceive fear, they can open their mouths wide, but there are other reasons as well. Is your chameleon also moving his head like mine is?

This head shake with the mouth open could mean that your chameleon is hot and trying to cool off. Sometimes they have respiratory issues that they can alleviate without our help or support.

This is a solitary creature who doesn’t depend on their counterparts to assist them when they are uncomfortable. Opening wide, and slight bobbing or moving of their heads helps them expel hot air.

Other reason include:

  • After eating
  • high or low temperatures
  • Before of after drinking
  • During the shedding of skin
  • Stomatitis
  • Injury
  • Heat stress
  • Metabolic bone disease (MBD)
  • Upper respiratory infection (URI)

The later possible explanations on this list above sound alarming and concerning. They might be possible causes if this yawning, shaking of the head or body is prolonged and coupled with lethargy or lack of appetite.

Chameleon Respiratory Infection

An URI or Upper Respiratory Infection occurs with reptiles in captivity when temperatures, poor husbandry, unknown illnesses or other factors lead to our pets feeling discomfort and unable to breathe well.

Bacteria from unclean enclosures or weakened immune systems can allow this unwanted infection to invade the lungs of chameleons or other reptiles.

Low temperatures and wet or humid enclosures are usually the cause for this condition if you believe their enclosure is kept clean and maintained well.

They might need the attention of a vet at this point who may administer or prescribe antibiotics to get rid of pesky, opportunistic and infectious bacteria that has found a home in your chameleon’s lungs.

Why Is My Chameleon Gaping?

Gaping is a version of jawing when a chameleon feels forced to defend themselves. Here are some reasons why your chameleons could be gaping, jawing or keeping their mouths open:

  • Perceived threats
  • New chameleon arrives and sharing is not desired
  • Pets routinely walk past the enclosure
  • Too many loud or unusual sounds
  • Doesn’t wish to be touched or handled
  • Drinking water
  • Shedding Skin
  • Overheating

Final Thoughts

An open mouth may make a chameleon look bigger and more fearful. They are trying their best to stand their ground when running away is not an option. Puffing their bodies up with their mouth open often indicates that this is the reason why their mouths are open wide.

A chameleon who drinks water in the wild, opens their mouths to allow drops from leaves or rain above to fall into their mouths, This is one of the ways a chameleon drinks. Asking them to quickly adapt to drinking from a bowl doesn’t always work. Mist the enclosure and allow them to slurp drops from nearby decorations or leaves.

Opening the mouth helps a chameleon loosen their skin in a tough to shed area around the neck. This could be happening during their shedding phase.

Overheating leads to a mouth open to expel hot air out. It works in some cases, but see how long they are stuck in this posture. Check temperature and make necessary adjustments if this behavior is prolonged.


Thank you for visiting for the best information to help you enjoy the life of your pocket pet companion in a fun, safe & healthy way.


My name is Anna and I work full time in my local pet shop where we sell many animals that I write about on this site. I love all animals and love writing about them.