6 Reasons Why Bearded Dragons Open Their Mouth

If you notice your bearded dragon sitting around with its mouth open, no, they aren’t mimicking a Venus fly trap. Similarly, if they start opening their mouth regularly, they aren’t trying to have a conversation with you.

So, what are they doing when they open their mouth?

Read on to understand the six main reasons why your bearded dragon may be opening their mouth. Most of them are nothing to worry about and represent normal behavior for your beardie.

why do bearded dragons open their mouths

In a few rare cases, it can be a sign that something isn’t quite right with your reptile friend and they may need a visit to the vet.

1. Thermoregulation

If you see your bearded dragon with their mouth open, the most common cause is thermoregulation. Like many animals, bearded dragons can’t sweat to control body heat. So, like dogs, they open their mouths to release heat.

You will usually see your beardie doing this while they are basking. They will sit in the heat and use it to raise their body temperature to somewhere between 95 and 110 degrees Fahrenheit.

When they get to a nice temperature, they might not leave the heat. Instead, they will open their mouth to drop their temperature a little. This practice is called gaping. When their temperature has dropped enough, they’ll close their mouths again and continue heating.

This doesn’t mean that your bearded dragon is too hot. They are doing exactly what they need to do to reach the right body temperature.

But if they continue gaping after they have retreated to a cooler and shaded part of their tank, then they are too hot. This probably means that your tank is too hot.

Ideally, the basking area in your tank should be around 95 to 100 degrees Fahrenheit, and the shaded area should be between 70 to 80 degrees.

But heat lamps should also be turned off during the night to allow for cooler temperatures. There should be enough radiant heat in the tank for your beardie until the morning.

So, unless your bearded dragon is gaping while in the shade, don’t worry about this behavior. If they are doing it in their shaded area, the first thing to do is check your terrarium temperatures.

2. Yawning Or Stretching

Just like humans and many other animals, bearded dragons will occasionally yawn.

They might do it in the late afternoon when they’re getting tired and ready for a sleep, or if they have been basking for a while and need to reinvigorate their bodies for a period of activity.

They might also just be giving their mouth and their beard a stretch. There are muscles in your beardie’s distinctive beard, and it can simply feel good to occasionally puff it up. They might even be practicing for later.

These behaviors are also nothing to worry about. But, as with most things, if they start doing this suddenly or excessively, it can be a sign that something has changed and is not right.

If you’re worried about unusual new behaviors, a visit to the vet can make sure everything is as it should be.

3. Shedding

Similar to stretching, your bearded dragon might open their mouth to stretch their neck in preparation for shedding. This action helps them loosen the skin for more room and can just make the whole shedding process feel more comfortable.

Bearded dragons shed fairly regularly up to the age of about 18 months because they are growing so quickly and need to expand their skin. They will start to shed less often as adults but will still need to do some wriggling to get out of their old skin.

Shedding is normal for bearded dragons and is no cause for concern. But you should monitor your beardie carefully when they are shedding to make sure they fully shed their skin so they can renew. Hard, abrasive objects in their tank can help with the process.

Read more about what to expect from the bearded dragon shedding process.

4. Aggression Or Stress

While aggressiveness and stress are two different emotions for your bearded dragon, they can invoke more or less the same behavioral responses, including opening their mouths.

If you have a single bearded dragon in captivity, even a male, aggressive behavior is relatively rare.

But if they come face-to-face with another beardie, especially another male, they will be compelled to get a little territorial. This will probably see them standing up tall, bobbing their heads, and opening their mouths wide.

Stress can cause similar behaviors as they adopt aggressive defensive positions. A surprisingly wide range of things can cause pretty severe stress on your bearded dragon.

Close contact with larger animals, such as cats and dogs, or with children, who they may have learned don’t have the gentlest of hands, can cause stress.

The problem is that these animals or children can’t detect your beardie’s stress response, so they’re unlikely to modify their behavior in response, and the stress may continue.

Bearded dragons are also very in tune with their surroundings, so changes in the area that surrounds them can be an additional source of stress.

Major contributors can be heavy sound pollution that leads to a stress response and light from other rooms at night that disrupts your bearded dragon’s sleep patterns.

Changes in your home decor can also set them off. They are very particular, and a new table or lamp might send their stress hormones through the roof.

Many bearded dragon parents also choose to put their terrarium next to a window to give their beardie a good view. But this can be a source of great stress as they deal with the constantly changing stimuli of the outside world.

Moreover, it is through these windows that they are more likely to see their natural predators, like birds. While the birds can’t get to them, beardies are genetically predisposed to feel stressed when they see them.

You can do your best to reduce potential sources of stress for your bearded dragon. Minimize noise and light pollution. Keep other animals and small children away from the tank.

Don’t give your beardie a view but instead keep them in a place in your house that doesn’t see much change. If you must invest in decorative changes, or move, prepare for a period of adjustment for your bearded dragon.

5. Mating Behavior

Even when your male beardie isn’t in the vicinity of any females, their hormones can go haywire in mating season, which is usually during the summer.

This can also result in mouth opening behavior that looks a lot like aggression, which is more or less what it is.

Mouth opening behavior is not a sign of romance at this time. Instead, they are entering competition mode to compete with other males for the best females. There may be no one to compete with, but they can’t help themselves.

Again, this is nothing to worry about since it is normal behavior. Just observe and enjoy this special part in their annual cycle.

6. Respiratory Issues

If your bearded dragon spends a lot of time gaping for no particular reason, this can be a sign of a respiratory issue, for which they will need a trip to the vet.

While these are relatively rare in bearded dragons, they are very serious and can be life threatening. They are opening their mouths to try to clear their airways, but they will probably need some help to properly recover.

The main cause of respiratory issues in bearded dragons are poor tank ventilation and excessive humidity. Properly controlling tank conditions can minimize the likelihood of your beardie developing this kind of issue.

Ideally, tank conditions should be kept at 35-40 percent humidity. This means that if you live in a humid climate, you will probably need a tank dehumidifier.

You can also minimize humidity by not keeping water in the tank for long periods and removing materials that retain water, such as bark.


Why does my bearded dragon open his mouth at me?

If your bearded dragon is responding to you by opening its mouth, it could be an expression of aggression or fear. Beardies don’t usually show aggression toward humans, but their normal behavior can be disrupted by captivity.

For some reason, they may see you as competition or as a threat. You can try and restore your relationship with them through gentle feeding, bathing, and playing.

Is it OK for my bearded dragon to have its mouth open?

If your bearded dragon is sitting around with its mouth open, this is probably nothing to worry about.

If they are in their basking zone, this is a method for letting off heat and regulating their body temperature. If they are feeling seriously overheated, they will head for the shade.

But, if they do go into the shade and continue to keep their mouth open, it’s probably a sign that their terrarium is too hot. Check heat levels and make sure they have good shaded spaces available. Don’t forget to turn off heat lamps at night.

How do I know if my bearded dragon likes me?

The strongest sign that your bearded dragon likes you is their level of comfort around you. If they trust you, they will remain tranquil when you handle them and will quite happily use you as a perch.

If they’re agitated when being handled or open their mouth, this is a sign of aggression and fear.

Why does my beardie close its eyes when I pet it?

While it may look like your beardie is enjoying themselves when they close their eyes during a good scratch, it’s actually a sign they are feeling tense and uncomfortable.

Closing their eyes helps them cope with the stress of the situation. You may see this progress toward more overtly aggressive behavior.

Why does my bearded dragon lick me?

Licking is a sign of comfort for bearded dragons. They feel safe around you and so feel comfortable to engage in exploratory behaviors. It should not necessarily be considered a sign of affection – they might also just like the way you taste or smell.

Why does my bearded dragon try to climb the glass?

Glass surfing is generally considered a sign of stress or aggression. It might be that their terrarium is too small and they are desperately seeking more space.

It could be that they encountered something threatening in the surrounding environment, such as a cat, and they’re feeling trapped. It could also be that it’s mating season and their hormones are making them more aggressive than usual.

How do I calm my bearded dragon?

If you have a stressed beardie, there are a few things you can do to help calm them. Start by reducing any sensory overload by removing noise and activity from their vicinity.

You should also minimize the amount of time you spend handling them and make sure they have no roommates with them in their tank.

When you do handle them, be gentle and let them explore you and get used to your scent. Bond through daily feeding and give them a gentle bath.

Understanding Bearded Dragon Body Language

While you might enjoy chatting with your bearded dragon, it can feel frustrating when they don’t chat back. But just because they aren’t communicating with words doesn’t mean they don’t have a lot to say.

Bearded dragons communicate a lot about what’s going on with them through their body language. Head bobs, waving, color changing, and tail pointing all tell you something about how your beardie is feeling.

Read our complete guide to everything you need to know about bearded dragons.

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