Bearded dragons are renown for being docile and friendly to their keepers. However, occasionally there are some pet owners that may find a suddenly aggressive bearded dragon straight after winter, as spring arrives. Seasonal aggression is likely to be a male, related to sexual maturity and the arrival of mating season. This seemingly angry outburst expected to be a short seasonal change.
Breeding male bearded dragons are not normally aggressive or angry towards their owner and if they are, it is more likely to be bluff (Brown, 2012).
Sometimes the unusual behaviour may start just before a year old and other times it might not be seen until the bearded dragon hits 4 years old. Aggressive hormonal behaviour is linked to males however, females can also become a little aggressive to a lesser degree.
Seemingly suddenly aggressive bearded dragon related to breeding will often start when it comes out of brumation, or at the beginning of spring. At this time, bearded dragons are ready for mating and hormone levels are up. The aggressive behaviours may last for a couple of weeks or longer.
Scent may have a significant part to play in aggressive bearded dragon responses. It was once thought that agamid lizards were mostly dependent on visual cues for their social interaction, however others have found that pheromones also have an important role to play (Gans and Crews, 1992).
The role of scent on the aggressive behaviour of the male Iberian wall lizards was studied by Lopez and Martin (cited Norris and Lopez, 2011). The scent of some males familiar with each other were masked with the scent of an unfamiliar male. This resulted in aggressive responses reserved for unknown males. When a male was introduced to another male masked with its own scent or even that of another familiar male, the aggressive responses were less aggressive.
9 behaviours that may be apparent in a male bearded dragon that has become suddenly aggressive with season may include:
- Blackening his beard and body.
- Bearded flared.
- Puffing up his body, tilting it slightly sideways to look bigger.
- Lashing tail.
- Mouth open, may include hissing.
- Running around and head bobbing.
- Clawing to get out of the tank, glass surfing.
- Suddenly lunging at a hand in the tank without warning.
- Attacking tank furniture or anything that comes near him.
Handling an Aggressive Bearded Dragon
If a bearded dragon becomes aggressive, no matter what the reason, it can cause considerable damage to fingers, or any soft flesh. It can quickly wrap its tail and legs around a hand and bite down.
It is best not to handle the bearded dragon until it calms down. In the case of seasonal aggression, the angry outburst could take a few weeks to return to normal. If the bearded dragon must be handled at such a time, use a towel or some other buffer between yourself and the lizard.
Where attempts to attack are made, record details of the event. For example:
- What was going on around him at the time?
- What color of clothing was being worn. Was there any black, red or other color?
- Was anyone wearing nail polish? If so, what color?
- What sort of scents may have been present? Any scents that a human nose could detect?
- Who was around?
- Was he indoors or outdoors?
- Was it in the enclosure, usual territory?
- Were there any other pets?
- Was there a reflective surface the bearded dragon could see himself in?
Note that in iguana’s, women’s menstrual cycle has been considered a factor for sudden aggression.
What signs of aggression did the bearded dragon display? For example:
- Black beard perhaps extending on the back and tail.
- Puffing up the body and tilting to one side to look bigger.
- Bobbing his head.
- Lunging at a hand.
Study the notes you take over time and look for patterns which can be used to prevent future events.
A suddenly aggressive bearded dragon is one of the main reasons that they should not be kept in small tanks with others. Passive behaviours as a bearded dragon grows does not prevent a sudden change of behaviours as hormones and other seasons changes take place.
In iguanas, sudden seasonal aggression is common. Male iguanas can see a male human as a threat to territory and may also try to defend access to human females in the household (Lock, 2018).
Suddenly Aggressive Bearded Dragon Outside of Breeding Season
Considerations for a suddenly aggressive bearded dragon not related to seasonal changes could be:
- Chronic stress (Benn et al, 2019)
- Accident, especially if the scent of another male bearded dragon is on the hands of the keeper.
Klaphake (UD) documented that in iguana’s impacted femoral pores could potentially be linked to sudden aggression. The evidence may be simply coincidental however, worth considering since impacted pores can cause considerable pain. Klaphake (UD) found that once the femoral pores were relieved the iguana’s behaviours returned to normal. Interestingly, the femoral pores secrete a waxy substance that gives away the most personal secrets. More on that in the post secrets of femoral pores.
5 Ways to Manage Seasonal Aggressive Bearded Dragon Behaviour
- Chances are you will not be able to calm the bearded dragon down, but you may be able to transfer the energy. Provide a stuffed toy or a small microwavable bean bag warmer. The bean bag warmer is ideal as it can be slightly warmed prior to giving to the bearded dragons. Ensure that anything provided will not present danger from being able to tear bits off or become a fire hazard. The toy may be attacked, mated or perhaps both.
- Cover reflective surfaces that may reflect the bearded dragon’s own image back to him. This could be seen as a rival.
- If there are other lizards in the same room, separate their habitats further.
- Temporarily reduce the lighting period to trick the bearded dragon into thinking it is not the right season for breeding.
- Avoid handling and allow the time to pass.
For information on the effects of desexing (neutering) on aggressive bearded dragon behavior see the post on spaying and neutering.
Suddenly Aggressive Bearded Dragon Conclusion
Although typically docile, a suddenly aggressive bearded dragon at the beginning of spring is likely due to seasonal changes cueing breeding time. This may not be the cause in all cases and each should be assessed on its own merits.
Consider the cues and stimulation the bearded dragon may be getting from the environment around him. Punishing aggression would be unjust and unproductive. If seasonal aggression is suspected, try the techniques above to prevent or deflect the bearded dragon’s aggression or energy.
Monitor and document the immediate environment and factors which appear to lead to aggression. Review the trends that are uncovered in the documented history to identify ways to prevent aggression in the future. Discuss with your vet.
If your pet is not aggressive, perhaps just scared, try taming a bearded dragon.
Has your bearded dragon become suddenly aggressive? Tell us your story in the comments.
- Benn, A. L., McLelland, D. J. and Whittaker, A. L. (2019) A Review of Welfare Assessment Methods in Reptiles, and Preliminary Application of the Welfare Quality® Protocol to the Pygmy Blue-Tongue Skink, Tiliqua adelaidensis, Using Animal-Based Measures. Animals (Basel). 9(1): 27.
- Brown, D. BVSc, BSc (2012) A Guide to Australian Dragons in Captivity. Reptile Publications. QLD Australia
- Gans, C., and Crews, D. (1992) Hormones, Brain, and Behavior. Bibliovault OAI Repository, the University of Chicago Press
- Klaphake, E. DVM, DACZM, DABVP (Avian Practice), DABVP (Reptile & Amphibian Practice) (UD) Femoral Gland Biology and Possible Medical Concerns in the Green Iguana, Iguana iguana.
- Lock, B. A. (2006) Chapter 13 – Behavioral and Morphologic Adaptations. Ed: Mader, D. R. Reptile Medicine and Surgery 2nd Ed. W.B. Saunders. Pages 163-179
- Lock, B. (2018) Aggression in Captive Reptiles. Veterinary Partner
- Norris, D. O., & Lopez, K. H. (2011) Hormones and Reproduction of Vertebrates Vol. 3. Reptiles. San Diego, CA: Elsevier Academic Press Inc
Friday 19th of November 2021
I have three beardies. Two were for my son and then I got two of my own. We named them after the ninja turtles and unfortunately, Michaelangelo passed away very young. I brought him back to the store when he passed, I only had it two weeks. I explained how I felt I did everything correctly and how the others were prospering just fine. I was so distraught when he passed away, I even tried giving it CPR to revive it. The person at the pet shop said it happens often. It was probably just sick already when I got it they felt. The first two, the ones I got for my son, have their own 40 gallon tanks and the whole hot/cool side. I have the UV bulb, a black heat light so when it’s night time I can leave the blue bulb on with it and heat is still emitted when the main lamp is off. (At night time when my son goes to sleep.) We were told they could be kept together, boy were they wrong! The one, Nacho (a..k.a. Rafael) was very bold and aggressive right from the get go. He was quick to eat and ate well. He hunted with passion and fury. The other one, Nelly (a.k.a. Donnatello) was timid and shy and at first, when we just had the two, I felt like she wasn’t gonna make it. She stopped eating all together and seemed “sad” or “depressed” even. I researched it and asked around at the local pet shops I frequented. Someone suggested taking their water out of the tank, so long as I did this every day-and giving them a bath. The guy said bearded dragons are known for not drinking water but that if I bathed them, they would absorb the water through their skin and it would hydrate them better. That did the trick. It also helped with bowel movements. I now give all three baths, sometimes together, usually not. Nelly and Leo get along and Nelly and Nacho seem to do the mating dance. (They’re the same age while Leo is still about two months younger.) I assumed Nelly is a female and the other two are males. That was until last night. My beardie Leo will sleep with me after nightly bath time. He gets all sleepy and when I wrap him in the towel he often falls asleep in it on my bed under my heated blanket. He will spend the whole night there with me like that. When Nelly was depressed, the baths worked so well but during that time I also bonded with her a lot. She slept with me too. (I didn’t have Leo yet) Nacho is the only one who hasn’t spent the night in my room yet. Last night, I gave all three of them baths and brought them all into my room to see what they would do. Leo fell right asleep as usual. Nelly and Nacho layed under the blanket for a while and then began to stir. They came out from underneath around the same time and then proceeded to do their little mating dance. But they never mate. Nelly whom I always thought was the girl got on top of nacho and was far more aggressive this time. Usually nacho gets on top of her and they fool around without actually doing the nasty. She crawled on top of him and licked his head and almost pushed his face into the bedding. I gently moved her off him. He looked relived. Then he started to wander over to me. Like he wanted me to pet him. I was on the other side of the bed. As he began to walk towards me Nelly got upset and lunged at him as if she were trying to prevent him from being near me. (I’m a female.) When she did that to him, he looked startled and so I lightly pet him to reassure him all was okay. It was a very bad mistake on my part. When I touched him she lunged for me and bit the hell out of my hand. I screamed and she let go. I put it back in its cage as well as nacho. I didn’t punish anyone. I was more shocked at what has just happened more than anything. She did draw blood. My hand hurts a lot and Leo slept through the whole thing. Lol. Does this mean she is not a she? I still don’t know which is what sex. They demonstrate both male and female characteristics. I can’t tell by looking at the pictures online then looking at them. Is the one that bit me always going to be aggressive now? Is it just possessive over the other? I didn’t realize it at the time, otherwise I wouldn’t have touched him. It was only afterwards reflecting on how he did come towards me and she tried to stop him that I realize it was her trying to keep me away from him or him trying to keep me away from her -whatever they are. Leo is still young but not that much younger than them, does it mean that he’s gonna turn into a giant a hole like they are? Or is he going to continue to be as Sweet and cool, the way he is now? They other two are only two months older but have changed drastically-overnight it seems. I’m not miss treating them, I’m not handling them wrong, they get tons of attention, they’re held every day, they get fed daily, they get vegetables daily- if anything, they’re spoiled. I don’t understand the sudden aggression, overnight it seems, and how can I find out what sex they are?
Thursday 29th of April 2021
I adopted my 5-year-old full-grown beardie about 3 months ago and he was timid at first but after a couple of weeks, he went with me everywhere then but overnight he became a totally different pet. He started going flinching at every movement and almost twitched at everything he saw move. He started running around his enclosure trying to climb out and showed signs of aggression such as; puffed up, black beard, and mouth gaping and hissing. I'm thinking it's because spring is coming but I'm worried I did something wrong. He used to be so loving and would cuddle but somehow I feel as if something triggered him to become so aggressive and defensive.
Friday 30th of April 2021
It is quite possible it is something to do with the environment. Might not be in his enclosure but something he sees. As much as it could be aggression, they are all signs of fear. Has the temperature got warmer lately? If so, possible that he was cooler before muting his reaction to anything going on and now it is warmer he is able to demonstrate his situation more clearly.
Sunday 29th of November 2020
Billy-The-Beared has never been particularly cuddly; but he’s never been this bad! He has a huge tank, with a warm and a cool side, natural branches, two ponds, edible live plants, UVB light, basking light, hiding places and so on. He gets fresh chopped veggies twice a day and about twenty or so mealworms and calci-worms also twice a day. He has grown like a weed and seemed very happy. What am I doing wrong??? He hisses and bites me and no longer likes being handled. Is it brumation? What do I do?
Monday 3rd of January 2022
@Catherine Prillo, Do you feed him Dubai Roaches and hornworms. I know mine love both. I don’t feed crickets because a lot of people say they are nasty and bite the bearded dragon. I hope you can get the help with your bearded dragon. We have a 7 months old bearded dragon who we are still working with taming.
Tuesday 22nd of December 2020
So much more to know to be able to provide a useful answer to you. I would suggest hormones may be kicking in and/or he is scared. Fast growth is related to diet. Size determines age more than calendar. This means that a 6 month old bearded dragon can have hormones going mad if it is large enough. Brumation is more likely to create a sleepy, lethargic bearded dragon than angry. Try putting a piece of cloth in the area with your scent over the next week or so and working your way from there, being extra patient. Best of wishes.