7 Reasons Bearded Dragon Keeps Opening its Mouth

Bearded dragons can exhibit a number of behaviors at any given time. However, they all mean something, depending on the lizard’s physical and mental state and the overall situation.

Today, we will look into the 7 most widespread reasons why bearded dragons keep opening their mouths widely. No bearded dragon does that without a good reason, so let’s look into the good reason.

Bearded Dragon Keeps Opening Its Mouth

If your bearded dragon keeps opening its mouth frequently, the first thing on the list is figuring out why. That’s because bearded dragons regulate their behavior based on their environment and what happens around them.

Learning why they engage in a particular behavior can explain their overall mental and physical state and the status of their ecosystem.

Here are the top points to consider when assessing your beardie’s mouth-gaping behavior:

1. Thermoregulation

If your bearded dragon opens its mouth frequently, that may be because it’s too hot. Bearded dragons rely on their environment to regulate their internal temperature. This means that their environmental temperature will directly influence their behavior and lifestyle.

If it’s too cold, the dragon will seek to warm up, usually migrating to the basking area or climbing their enclosures’ structures to get closer to the light bulb.

If it’s too hot, the reptile may bathe in its water bowl or hide in the shade, preferably in its hiding spot. The mouth gaping behavior is also a way for the bearded dragons to regulate their body temperature by exposing the interior of the mouth to the outside air.

The interior of the mouth is always warmer than the outside, which means that the cooler air will reach cool off the blood reaching the mouth.

The cooler blood will then spread throughout the circulatory system, dropping the lizard’s core temperature as a result. Dogs exhibit the same when panting, which is a behavior meant to cool off an overheated circulatory system.

You will notice that your dog will pant more aggressively the hotter it is, and the same goes for the bearded dragon.

So, always check the reptile’s environmental temperature if you notice the lizard gaping its mouth frequently.

Overheating is a serious danger in bearded dragons, as it can lead to severe dehydration, which can get deadly fast.

2. Sign of Aggression

Bearded dragons usually gape their mouths at each other when exhibiting aggressive behavior. This includes territorial, food, or mating-related confrontations, which typically describe the interactions between male lizards.

Females will also fight, though, as fighting isn’t a male-specific behavior. Males just have more reasons to fight than females.

However, bearded dragons may not exhibit violence towards each other exclusively. They may also showcase the same behavior toward their handlers. Bearded dragons are typically docile and friendly, but that can change depending on the situation.

Here are some situations that may warrant a bearded dragon’s aggression towards you:

  • Not respecting its privacy – Bearded dragons are reptiles first and foremost. Keep that in mind next time you want to play with it. They might accept some handling and petting and might even be thrilled about it, but you should understand the importance of giving the lizard space. Bearded dragons aren’t as affectionate as dogs, for instance, and can quickly get stressed and aggressive if mishandled or petted for too long.
  • Dealing with a new home – Bearded dragons can get stressed when first brought into their new home. That’s because they aren’t yet accustomed to their new setup and need time to learn their ecosystem. Avoid any interactions during this time so that your beardie doesn’t feel the need to react aggressively.
  • Improper setup – If the housing setup isn’t up to par, the reptile will become stressed and even aggressive. The animal’s housing conditions should mimic its natural ecosystem, with climbing areas, at least one hiding spot, and sufficient space for a comfy sitting.
  • Improper parameters – Always adjust the lizard’s environmental conditions, aka temperature, humidity, lighting, and aeration. If not, your beardie will show its discontent via mouth gaping and even biting.

As you can tell, patience and knowledge are the most critical tools when dealing with bearded dragons.

3. Stress and Anxiety

Bearded dragons may also use mouth gaping to vent out their stress, anxiety, and frustration, depending on the situation. Stress is a common problem among reptiles in general, primarily because of their secluded lifestyle and solitary nature.

Bearded dragons prefer peace, safety, and comfort above all else. If these conditions aren’t met, they will exhibit stress and signs of anxiety, which are indicative of a deteriorating mental state.

Stress is a silent killer when it comes to reptiles because it destroys their immune system and opens the door to an entire array of issues.

You can tell that your beardie is stressed if it refuses to leave its hiding spot, lacks a healthy appetite, appears irritated and aggressive, exhibits low activity levels, etc.

Many bearded dragons can also become slightly darker or even black when stressed.

4. Beard Stretching

This is the equivalent of yawning in humans, or close to it, at least. In short, bearded dragons open their mouths simply as means to stretch their beards, which is a way for them to relax and release tension.

It’s nothing to worry about, as it is a natural behavior. This behavior only begins problematic if it repeats too often, leading to the idea that something else might be at play.

In that case, you should look for other signs that may indicate the nature of the problem.

5. Mating Season

Bearded dragons exhibit a variety of behaviors during the mating season, depending on their intentions and even sex. The gaping mouth has several potential explanations, depending on the lizards’ sex.

If males do it to each other, this is a clear sign of aggression and competitive behavior. The gaping mouth is supposed to intimidate, as are posturing up and becoming black in the process.

If the male and female open their mouths toward each other, they may simply be communicating their intentions. When males do it, it’s to attract the female’s attention. When females do it, it’s usually a sign of acceptance, although it can also mean rejection if the female isn’t content with the pretender.

The difference in intentions can be understood by looking at other behaviors. If the female appears aggressive towards the male, this adds a different meaning to the gaping mouth.

6. Craving for Food

Bearded dragons can also keep their mouths open when hungry because they have no other way of informing you directly of their predicament.

Don’t mistake this with aggressive posturing due to stress or simply hating your presence at that moment in time. To figure out whether the lizard is hungry, check out other potential tell-telling behaviors like licking its lips constantly and looking for something around the enclosure.

This is a sign that the lizard’s mind is in a food-searching state. But what should you do if the lizard exhibits this behavior despite having just eaten recently? Well, it’s simple: feed it more often.

Young bearded dragons typically eat 1-3 times per day, depending on their age and metabolic activity. Adult lizards may eat once every 24-72 hours, and this discrepancy is due to several factors, including age.

But the lizards’ feeding behavior can also vary wildly between different individuals, despite them being of the same age and size. Some lizards simply have larger appetites, and there’s nothing you can do about it than satisfy them.

Just make sure you don’t slip into the other extreme and overfeed your lizard.

7. Respiratory Infection

Respiratory infections are a reason for serious concern among bearded dragons. If experiencing respiratory infections, bearded dragons may exhibit a variety of behaviors, including mouth breathing.

This is necessary to circumvent the inflamed nasal passageway that makes normal breathing difficult or even impossible.

Bearded dragons may contract a respiratory infection for several reasons, but most relate to poor enclosure hygiene. This leads to the accumulation of bacteria and fungi, which infect the lizard’s airways and respiratory system.

A dusty substrate releasing endless dust particles in the air is another potential cause with equally damaging effects.

You can tell that the bearded dragon exhibits difficulty breathing if it’s coughing, wheezing, sneezing, and displaying nasal discharge.

The latter is particularly worrying because it suggests a potential infection, and respiratory infections can develop into pneumonia. I recommend contacting the vet for personalized treatment.


You should always understand your bearded dragon’s behaviors because there are quite a few to go around.

When it comes to mouth gaping, some potential explanations demand closer inspection and should rank higher on the urgency list.

Respiratory infections and overheating occupy the top of the list due to their severity and high danger factor.

Robert from ReptileJam

Hey, I'm Robert, and I have a true passion for reptiles that began when I was just 10 years old. My parents bought me my first pet snake as a birthday present, which sparked my interest in learning more about them. read more...