Chameleon Behavior: Gaping

Chameleon is holding its mouth open ; Gaping


Chameleon holds it’s mouth open.


Meaning: An open mouth can mean anything from a fight response to a serious and deadly medical condition.


  • Chameleon feel threatened and is warning that it will defend itself
  • Chameleon is too hot and is trying to cool off
  • Chameleon is having difficulty breathing

Gaping can meaning many different things depending on the context. Read further to determine the context of what you are observing.

Podcast Discussion

Click the player below to listen to a discussion about troubleshooting a gaping chameleon and how you can figure out what it means.

Threat Display

When a chameleon feels threatened it will both try and make itself look as big as possible and warn that a bite is imminent. If it is a threat display the gaping will be accompanied by an inflating of the gular (throat,) a flattening of the body, bright colors, and the front hand (or hands) being drawn up into the body.

This is not a reason to worry other than a sign that you should remove the stressor. If it is you invading their cage space to give them food then they will get over it when you retreat. If they are reacting to a pet bird, for example, then change the cage location so they do not have whatever they feel threatened by around them. This can often happen in situations where chameleons are kept together. in the same cage. the solution, of course, is to separate the chameleons into their own cages and put up a visual barrier if there still is an issue.

chameleon gaping

This Panther Chameleon is giving a half hearted warning of being annoyed. She does not like human intrusion in her cage, but has been raised from the egg being served by this human so she does not seem to have much vigor behind her warning.

mellers chameleon gular

This Meller’s Chameleon is in a defensive display trying to make itself look as big as possible and warning of a bite.

veiled chameleon warning gaping

I don’t think there is any ambiguity in the intention of this female Veiled Chameleon. She has gone past the defensive state and jumped with to the offensive. There is no warning about an incoming bite. She is actively search to a target to bite.

Temperature Regulation

When temperature gets beyond the chameleon’s comfort level they will try and cool themselves off. They do this by moving lower in the cage towards the shade and moist Earth, they will make their colors as light as possible to reflect sun, and they sit with their mouth open to try and get the hot air out.

This is a warning sign of a harmful and potentially deadly situation. This is a sign of overheating and you need to provide the means for the chameleon to cool off. Gaping is the second to last step. Eyes closed and body shutting down is the next step so if it is hot and you see gaping act immediately.

Overheating is very common when owners move their indoors screen cage out to give their chameleon some natural sunlight. With no cover and a floor that reflects the sun’s rays, the chameleon can easily overheat even if you are comfortable.

If you see a chameleon overheating get them to a cooler location immediately.

heat gaping jacksons chameleon

This Jackson’s Chameleon is gaping to cool down.

chameleon with washed out colors

This  Kinyongia multituberculata is showing washed out colors and is gaping to try and cool down his body. When we restrict our chameleons to a relatively small space we must provide them with the temperature gradients within their comfort range.

Difficulty Breathing

An unfortunate reason to see a chameleon gape is if they are in the final stages of respiratory infection or other lung based medical condition. With infection or other substance in their throat and lungs they are trying to gulp as much air as possible.

Any open mouth breathing is a red flag that you need to get to the vet as soon as possible.

The stages of Respiratory Infection

  1. Nose is in the air to help straighten throat to aid in breathing. This is the time to start treatment.
  2. Open mouth breathing when they are alone. They are sick but can still pretend they are healthy. Treatment has high percentage of success.
  3. Gaping even if you are in the room. Life is measured in days. Get to a vet. recovery is 50/50
  4. Eyes closed while gaping as their body is shutting down. This is an emergency and you have hours until death.

Any gaping due to illness is serious. And, be careful with the diagnosis. Viral infections can have the same symptoms as bacterial and the antibiotic treatment will be useless.

Jacksons possible RI

The initial external stage of respiratory distress is the nose pointing up into the air to make it easier to breath. Unfortunately, the infection has been going on before this external symptom manifests. It is important to act quickly.

Trioceros deremensis chameleon with respiratory infection

As the respiratory distress continues the chameleon will breathe through their mouth. But they will still try and hide it when they see you. As the condition progresses they will not be able hide it. You will also notice their eyes sinking in. Their life is now measured in days. Treatment at this point is possible, but your probability of success is dwindling significantly by each day you do not take action.

Meller's Chameleon with respiratory infection

This is a sign of a chameleon who has only hours to live