Understanding Your Bearded Dragon’s Open Mouth Behavior

Open mouth behaviour in Bearded dragons can be quite intimidating and even threatening, but there might be other reasons for this to happen. This behaviour can either be normal, threatening or indicative of environmental problems.

As with most other animals, the mouth’s main function is to take in food and water. It has been constructed to be closed most of the time, but with Bearded dragons there might be various other reasons why their mouths are open. These include thermoregulation and threatening behaviour.

What Is Gaping In Bearded Dragons?

Gaping is a behavior commonly seen in Bearded Dragons. It is when a beardie leaves its mouth open for an extended period of time, usually while they are basking under a heat lamp. This is done to regulate their body temperature as Bearded Dragons do not have sweat glands. Gaping allows them to release excess heat through their mouths and maintain their ideal internal temperature.

Although gaping isn’t something you should be worried about, it can be a sign that your bearded dragon’s tank may be too warm if they are doing it on the cooler side of the tank. In this scenario, you may need to adjust the temperatures accordingly – keeping the cool side of the tank between 75 and 85 degrees Fahrenheit during the day and between 70 and 75 degrees Fahrenheit at night; meanwhile, making sure that the basking side stays between 88 and 100 degrees Fahrenheit.

If proper action isn’t taken after observing this behavior then it could mean serious consequences for your bearded dragon’s health so always keep an eye out!

Why Do Bearded Dragons Leave Their Mouth Open?

Bearded dragons regulate their body temperatures by opening their mouths wide. It’s the only way for them to thermoregulate and stay comfortable. Without this ability, your beardie would struggle to digest food properly or carry out any necessary bodily functions.

If you’re new to taking care of a bearded dragon, you may have been taken aback the first time you saw them with their mouth open. But once you understand why they do this, and that it’s perfectly normal behavior for them, it puts your mind at ease. Your dragon leaves its mouth open because it needs to control its own internal temperature – so you can be sure that your pet is happy and healthy!

Open mouth basking

It is quite normal to see a Bearded dragon bask with its mouth open. Because Bearded dragons cannot sweat, they need other ways to get rid of excess heat. By opening their mouths, excess heat can escape through their breath and the body is cooled down to a more comfortable temperature.

This behaviour is normal as long as the Bearded dragon spends a lot of time in the basking area. When a Bearded dragon spends most of its time hiding or on the cooler side of the enclosure, it can be indicative of too high environmental temperatures.

Threatening behaviour

Bearded dragons also open their mouths when they feel threatened. By opening the mouth the head looks a little bigger and the readiness of biting is clearly indicated. Open mouth threatening behaviour is commonly seen with scared, injured, irritated or intimidated Bearded dragons. Other signs of threatening behaviour includes the fast form of waving, making hissing sounds, dashing forward and flattening of the body. Some Bearded dragons might even bite! Some of these signs might also be seen as part of territorial behaviour.

Although uncommon, aggressive individuals may appear from time to time in pet Bearded dragons. Regular careful handling might help to reduce this behaviour. When a Bearded dragon is scared, injured, irritated and/or threatened open mouth behaviour should be seen as a warning sign.

Open mouth breathing

A third reason for open mouth behaviour in Bearded dragons is that the environmental temperature is too hot. In this case it is more accurately referred to as open mouth breathing and is more serious and can be life-threatening if not rectified immediately. Also see the  Bearded dragon temperatures article for more information.

Reasons Why Bearded Dragons Hold Their Mouths Open

If your bearded dragon is keeping its mouth open, it could be a sign of discomfort, anxiety, or an attempt to regulate its body temperature. Here are 10 potential explanations for why this behavior occurs.

1. Gaping For Temperature Regulation

Bearded dragons use gaping as a way to manage their body temperature. When bearded dragons sit with their mouths open, they are usually trying to regulate their body temperature, which is called “gapping”. This behavior allows them to dispense the extra body heat they have built up and return to their optimal state.

Bearded dragons don’t cool down in the same way that we do, as they cannot sweat to control their body temperature. When they have reached their ideal body temperature, between 95-110 degrees Fahrenheit, which you can usually see when they’re basking fields under a heat lamp, for example, this gaping allows them to not overheat any further.

2. Stretching and shedding

Bearded dragons need to stretch on a regular basis, and this is a crucial step in helping them shed properly. When they stretch their jaw muscles, they open and close their mouth in shorter intervals compared to when gaping. This helps them loosen up their skin before the shedding process starts.

The activity level of bearded dragons tends to slow down during the shedding process too. It’s important that they still have plenty of space to stretch while they’re going through shedding so that they don’t get stuck with dry patches of skin. Regular stretching will help remove these problem areas and ensure your pet can make it through shedding comfortably with as little stress as possible!

3. Mating Season

Bearded dragons are known to display a natural behavior during the mating season. During this time, they tend to become more aggressive and have their mouths open wide. You’ll likely see them becoming territorial if people or pets come near their enclosure, as it’s all part of their mating process.

Unfortunately, there isn’t much you can do about this; it’s simply part of nature and something that comes with bearded dragons mating!

4. Sign of Aggression

Bearded dragons are generally gentle creatures, but if they sense a threat, they may show aggression in the form of an open mouth. If you notice your bearded dragon’s mouth gaping wide with bared teeth and dark beard, this is definitely a sign that they are feeling aggressive.

When threatened or feeling defensive, these lizards will puff out their chests and spread their beards to make themselves look larger and more intimidating. In addition, they may bob their head rapidly as another sign of aggression.

5. Respiratory Disease

Respiratory disease can be a serious problem for bearded dragons. If your dragon has to breathe with its mouth open, this is a sign that something isn’t quite right. While respiratory problems are more common in other reptiles, like snakes, it’s still important to get your pal checked out if you notice this behavior frequently.

If you notice any additional symptoms such as lack of appetite, not moving around much, mucus near the eyes or nose, coughing, wheezing, or crackling sounds while breathing, it’s time to see the vet ASAP.

6. They’re Responding To Another Dragon

Bearded dragons will often open their mouths in response to another dragon. This behavior is common amongst territorial creatures, and because two beardies are kept together in the same tank, one will attempt to assume dominance over the other.

The dominant one will use its mouth as a display of power and strength, while the less dominant dragon may become stressed and stop eating.

How to Tell if Your Bearded Dragon is Gaping

It’s easy to tell when your bearded dragon is gaping, if they’ve been basking in the sun for a few hours and you spot an opened mouth then it’s likely that your little dragon is gaping. Gaping, in beardies, is a natural response to heat affecting their body temperature and the open-mouthed posture enables cooler air to enter their mouths.

By keeping an eye out for their behavior, particularly during periods of basking at higher temperatures, you can easily tell if your pet dragon is gaping or not. If your bearded dragon begins breathing heavily and its mouth opens wider than usual that’s a clear indication of gaping.

What To Do If Your Beardie Is Gaping

If you observe your bearded dragon gaping, don’t stress! This strange behavior is perfectly normal for these animals and is often seen under their basking lamp.

In fact, it’s one of the quirky behaviors that all bearded dragon owners come to appreciate. It may even provide a great photo opportunity where you can get close enough to see their little dinosaur teeth! So, if your beardie is gapping, there’s no need to panic – it’s just another one of their cute habits.

Is it bad when a bearded dragon opens its mouth?

It’s natural for a bearded dragon to open its mouth every once in a while, and usually, this isn’t an indication of anything bad. Usually, they do it to regulate their body temperature, or as a display of aggression or distress. There are very rare occasions when it may point toward a respiratory infection, so be sure to keep an eye out for any other warning signs.

If you spot your bearded dragon opening its mouth repeatedly or often, then it’s worth consulting with a vet just to make sure all is okay. Otherwise, there’s no need to worry when your pet opens its mouth from time to time – it’s totally normal!


Do Bearded Dragons Sleep With Their Mouth Open?

Generally, beardies don’t sleep with their mouths open; but if it happens, it might be a sign that your dragon is too hot during the night or just a personal trait.

Why Is My Bearded Dragon Sticking His Tongue Out?

Bearded dragons often stick out their tongue to explore their surroundings. This is done by extending and retracting their tongue to gain information about new objects in their environment.

Do bearded dragons open their mouth when happy?

Bearded dragons will often open their mouths to establish a comfortable temperature, not indicating that they are content. In fact, it may indicate aggression or distress instead. It may also be indicative of a respiratory issue.


In conclusion, bearded dragon open mouth behavior is a common occurrence, and can be an indication of a variety of things. While some instances could signify illness or stress, they could also simply be part of the bearded dragon’s natural ways of regulating its body temperature.

The best thing to do as a pet parent is always observed your reptile closely and do research when you notice anything out of the ordinary.