bearded dragon handbook

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Every Reason Why Your Bearded Dragon Is Aggressive

Although bearded dragons are known for being calm, friendly reptiles, they also have the potential to become aggressive due to various potential stressors in their habitat. 

So what exactly causes this combative behavior in these normally docile dragons, and what should you do to soothe such an angry, uncooperative lizard? 

The primary reasons for aggression in bearded dragons are prior abuse or neglect, poor handling or diet, improper enclosure setup, untreated illness, brumation, and various environmental stressors such as cohabitation or loud noises.

If your beloved beardie has been acting out, don’t panic, and keep reading. 

We’ll cover all of the possible reasons your lizard is displaying aggression and what to do to make them more comfortable and less stressed. 

why is my bearded dragon mean

What Causes Aggression In Bearded Dragons?

Despite being commonly held up as the calmest and most friendly reptile species ideal for beginners, aggressive behavior in bearded dragons is more common than you’d think. 

Thankfully, most of the causes are temporary and are easily solved simply by paying close attention to and addressing your pet’s needs. 

There are several potential causes of aggression in these expressive reptiles, with most of the reasons being tied directly to your pet’s environment and how you interact with them. 

Perhaps your beardie came from an abusive or neglectful home and is taking some extra time to warm up to you. 

Maybe they’re ill or upset due to an improper diet and chronic malnutrition.

Or maybe brumation is nearing, and your beardie just isn’t feeling up to interacting with you as much as they usually do. 

Many causes of sudden hostility in bearded dragons are surprisingly mundane and easily prevented by slightly adjusting the way you interact with your pet.

Yet another possible cause is improper handling in general; if you’re being too rough with your lizard, picking them up too quickly, or even just making too many sudden movements or loud noises, your dragon will often respond with anything from mild irritation to outright fury at your behavior. 

While they certainly are very docile animals, bearded dragons greatly appreciate and benefit from a calm environment with as few stressors as possible. 

It’s best to break down every potential cause and rule them out one by one to pinpoint the exact reason why your dragon is displaying aggressive behavior.

  • Is the aggression a new occurrence, or has it been going on for a long time? 
  • Have you changed anything in your beardie’s enclosure or general environment lately? 
  • Has your dragon suddenly lost weight recently or displayed any symptoms of illness? 

These are good questions to ask yourself when determining the cause (or causes) of your pet’s irate attitude.

It helps to understand aggression as simply a manifestation of stress. 

When an animal is experiencing stress, they typically act out aggressively. 

Thus, as a bearded dragon owner, you will need to address and minimize any stressors in your lizard’s environment accordingly. 

Improper Handling

One of the most common reasons a bearded dragon behaves aggressively is improper handling. 

While beardies definitely tolerate and even enjoy being handled far more than most reptiles, they still have to be handled with care to prevent them from becoming stressed or uncomfortable.

When picking up your beardie, look at them to see if they’re already displaying hesitation or fear as you approach them. 

If their beard is black or their mouth is gaping, it is best to avoid them and allow them to calm down first.

Never approach your lizard from above, as they will interpret shadows overhead as a potential predator attack and either flee or possibly attempt to bite in perceived self-defense.

Reach towards them from the side very slowly and carefully slide your hands underneath their belly and limbs to support their entire body. 

Never pick them up by the head or tail; pay special attention to these more fragile body parts when handling a bearded dragon.

Sometimes handling a bearded dragon for too long will exhaust and upset the animal. 

If your lizard starts to squirm or attempts to run away, it is probably best to put them back in their enclosure. 

Further Reading: How often to handle bearded dragons to avoid stress

Calmly handling your beardie for short periods at a time in a quiet, well-lit (but not too brightly lit!) environment is best to slowly build trust with them and teach them you aren’t a threat.

Stroke their head or back gently and speak in a low, quiet voice to calm your dragon as you hold and handle them. 

Avoid touching or prodding at their mouth, limbs, and tail. 

Just as you wouldn’t appreciate any sudden loud noises or movements in your personal space, your beardie won’t like them, either. 

We have a post on how to pick up bearded dragons as a guide to the process if you want more information.

Illness Leading to Aggression

It is essential to observe and get to know what is considered normal behavior for your beardie to address any sudden changes as necessary. 

Illness is another common cause of aggression in bearded dragons (or any pet in general).

Observe your dragon for any changes in their behavior, sudden weight loss, or frequent black bearding, as these are sometimes indicators of potential illnesses. 

If your beardie has parasites, a respiratory infection, or mouth rot, to name just a few common illnesses, they will typically display changes in their behavior and not enjoy being handled as much as usual.

One of the most common illnesses in reptiles is metabolic bone disease. 

If your dragon isn’t getting enough calcium in its diet or proper UV lighting, its bones will deform over time and become prone to fractures, causing the lizard to become weak, shaky, and lethargic. 

When left untreated, this illness will become extremely painful and eventually fatal.

If your bearded dragon displays any of the following symptoms, an illness is likely to blame for its aggressive behavior. 

Contact a reptile veterinarian and schedule an appointment as soon as possible.

  • Sudden weight loss
  • Sneezing
  • Diarrhea
  • Runny discharge from the eyes, nose, or mouth
  • Weakness or trembling
  • Constant “black bearding”
  • Unusually shallow or rapid breathing
  • Low or no appetite
  • Ticks or mites on the dragon’s skin
  • Swollen or red gums
  • Rubbery limbs or bone fractures

Check out our post on bearded dragon diseases for a comprehensive list of illness’s causes and solutions.

Prior Abuse or Neglect

Did you purchase your bearded dragon secondhand or from a pet shop? 

If so, there’s a possibility they’ve come from an abusive or neglectful environment. 

The easiest way to spot this is if they have any tail nip or toe nip where these areas are damaged.

You can learn more about bearded dragon tail nip and toe nip in a separate post of ours.

It’s best to only purchase reptiles from reputable breeders, so you’re able to verify exactly where and from what kind of home your dragon comes from, but in the case of many rescues, this isn’t always possible.

If your beardie has come from a less than ideal home before ending up in your care, be very patient with them and handle them slowly over time to gain their trust. 

Abused or neglected dragons come to expect poor treatment from humans over time, causing them to become distrustful and even hostile towards anyone who attempts to handle them.

If your dragon is taking some extra time to warm up to you, offering them treats like fruits, insects, or other foods beardies typically enjoy will help them learn you aren’t a threat. 

Simply sitting beside your beardie’s enclosure and being near them will also help establish yourself as a friendly presence.

Over time, your dragon will slowly allow you to handle them more and eventually pick them up.

Just be extra patient if your lizard has experienced abuse or neglect in the past, and allow them to come to you rather than overwhelming them with too much stimulation. 


For adult bearded dragons, brumation is a common cause of grumpy or even aggressive behavior. 

When preparing for brumation, beardies often become more lethargic and standoffish than usual and have a significantly decreased appetite.

When the colder months approach, you’ll probably notice your beardie beginning to sleep more and eat less than they usually do. 

They’ll also hide in the corners of their enclosure, tending to avoid their heat and UVB lighting.

During and in the weeks leading up to brumation, it’s best to give your dragon space and avoid handling them as much. 

They’re essentially preparing themselves for a reptile’s version of hibernation, so if they seem less interested in you, it’s perfectly normal. 

Let your dragon brumate in peace and resume normal handling when they emerge from their slumber.

The length of time your dragon will brumate varies from individual to individual. 

Some lizards barely rest at all, while others will sleep for weeks on end, barely moving a muscle, only emerging very briefly for water and small amounts of food. 

Our guide on bearded dragon brumation is very detailed and informative if you want to learn more about the ins and outs of brumation.

Malnourishment & Poor Diet

A proper, varied diet is essential to your dragon’s health and happiness in general. 

Another common cause of aggressive or abnormal behavior is a poor diet. 

Bearded dragons require a wide range of foods for a balanced diet, including a base of primarily leafy greens, plenty of other safe vegetables, insects, and a small number of safe fruits.

Weighing your dragon weekly will also help you determine if they need to gain or lose weight. 

If your beardie is eating too many fatty insects and not getting enough greens in their diet, they will become overweight or obese. 

On the other hand, if they aren’t getting enough protein and fat from the insects in their diet, they will become thin and malnourished.

Research exactly how much of each food group your beardie needs and stick to a regular feeding schedule. 

Generally, they should be primarily eating dark, leafy greens, with the rest of their diet being made up of vegetables, insects, and fruit. 

If your beardie is overweight or underweight, reduce or increase their food intake accordingly. 

Read our bearded dragon diet sheet for a complete list of optimal foods for your pet.

Relocation Stress

Have you recently moved or relocated your bearded dragon? 

If so, it is normal for your pet to be experiencing feelings of stress. 

It’s best to avoid excessive handling immediately after a significant move or relocation, whether you’ve moved across state lines or have merely moved your beardie’s enclosure to another room in your home.

Remember, even if the move seems minor to you, to your beardie, it’s worlds away from what they were used to. 

Don’t introduce any additional stress to their environment for at least a few days after moving the lizard to a new location. 

Give them time to explore their surroundings, mainly if they live in a glass tank and are able to see out of the enclosure.

Slowly reintroduce yourself and gentle handling into your beardie’s routine once they’ve become more comfortable in their new habitat. 

Over time, their aggression and discomfort will subside. 

Gravid Female Bearded Dragons

If you have a female bearded dragon and you’ve bred her with a male recently, she might be expecting! 

Being gravid is a stressful experience for any animal, and bearded dragons are able to lay anywhere from five to as many as 20 eggs in a single clutch!

Your beardie will likely display the following symptoms in addition to mild aggression: 

  • Pacing back and forth throughout their enclosure 
  • Digging or scratching. This is usually indicative of the lizard seeking out a spot to bury her eggs.
  • Resistance to being handled; squirming or running from you when you attempt picking her up is common.
  • Increased appetite 
  • Territorial behavior, particularly if you attempt to go near or touch her dig box 

It is best to avoid handling a gravid female at all until she has finished laying her entire clutch. 

Provide her with plenty of calcium and nutritious foods to support her growing body, and contact a reptile vet as soon as possible if she becomes egg-bound or displays any signs of illness, severe malnutrition, or dehydration. 


In general, it is best to avoid cohabitating multiple bearded dragons in the same enclosure entirely, even if they happen to be a breeding pair. 

These lizards are solitary animals who benefit most from being the only animal in their enclosure.

Introducing other dragons to their tank will almost always introduce unnecessary stress, anxiety, and competition for resources, especially if the tank is not large enough for two bearded dragons.

Keep your beardies to one per tank to prevent them from becoming hostile and aggressive towards you and each other. 

However, if you’re thinking about breeding we have a post on male and female bearded dragons living together you’ll want to check out.

Improper Enclosure Size

A good rule of thumb to remember with bearded dragons is 40 gallons or more per lizard. 

Ideally, a tank of around 55 to 60 gallons is best, but at minimum, the tank should be no smaller than 40 gallons.

If your beardie’s enclosure is too small, they will become stressed by the lack of space to move, eat, hide, and sleep. 

Be sure they have plenty of room to feel comfortable, but don’t overwhelm them with a huge enclosure they’ll get lost in, either. 

Anything larger than 75 gallons or so for a single bearded dragon is unnecessary. 

Other Environmental Stressors

If you’ve ruled out all of the above causes of aggression, look to your beardie’s environment for any other potential stressors. 

There are many questions you should ask yourself when assessing your pet’s environment.

  • Is something in your dragon’s enclosure bothering them? 
  • Is another pet in the room near their enclosure stressing them out? 
  • Has anything changed in their routine recently? 
  • Are the temperature and humidity in their enclosure within a normal range? 

Some bearded dragons happen to naturally be friendlier than others, but it’s rare for any beardie to display serious aggression completely unprompted unless they’ve experienced severe, repeated abuse or neglect.

Always ensure your lizard’s habitat is as comfortable as possible and set up appropriately when it comes to lighting, temperature, humidity, and the environment surrounding their enclosure. 

Related: Why Is Your Bearded Dragon Sleeping Upright?

Even being set up a little too close to another reptile’s enclosure will potentially add unnecessary stress if the two animals are able to see each other through their terrarium glass. 

How Aggression Manifests In Bearded Dragons

Bearded dragons express their anger in many different ways. 

You now know the potential causes of aggression, so you should also understand how to recognize displays of aggressive behavior.

Some behaviors indicative of aggression, discomfort, and stress include the following: 

  • Black bearding. It is common for angry bearded dragons to flare out their beards in an attempt to ward off predators and perceived threats. 
  • Hissing 
  • Lunging or tail whipping 
  • Biting. Bearded dragons have two extremely sharp rows of serrated teeth, so be careful! 
  • Head bobbing. This behavior has many possible meanings, from territorial displays to potential interest in a mate, but it also sometimes is indicative of aggression, particularly if the head bobbing is more rapid than slow and deliberate. 
  • Avoidant behavior. If your beardie generally just seems resistant to being approached or handled, it’s best to leave them alone rather than persisting with your attempts to touch them or pick them up. Reapproach your lizard later in a more slow and gentle manner.

Remember, an aggressive bearded dragon is usually just really stressed out, so be gentle, kind, and patient with them. 

Adjust any potentially stressful environmental factors accordingly, and be especially vigilant for signs of illness or malnutrition. 

How To Handle An Aggressive Bearded Dragon

If possible, it’s best to avoid handling an aggressive bearded dragon excessively, at least at first, particularly if they are attempting to bite you or are lunging at you whenever you approach them.

First, go through all of the potential causes of their emerging aggression one by one. 

Rule out as many as possible, and address whatever causes are remaining. 

See a reptile vet if an illness is an underlying issue, and be extra careful when moving or interacting with the lizard.

If environmental causes are to blame, your beardie will likely become more docile after you have identified and eliminated their stressors. 

It will probably take them a few days or even weeks to warm up to you and trust you, but be patient. 

Remember, reptiles don’t express their emotions in the same way other common pets like cats and dogs do.

Your beardie might not be willing to allow you to pick them up and hold them initially. 

Put your hand in their tank for a few minutes at a time to get them used to your presence. 

Gradually progress to gently petting their head or back until they are comfortable with you picking them up and holding them without displaying aggressive behaviors.

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