The Gila monster, Heloderma suspectum, is a venomous lizard found in northern Mexico and the southwest United States.
It is one of only two venomous lizards in North America, the other being the Mexican beaded lizard.
Are Gila monsters aggressive? Gila monsters are considered fairly docile, and are not considered aggressive except when threatened or cornered. They will usually warn you before they bite by facing you with an open mouth and hissing. This defensive display is not a bluff. Handling a Gila monster might result in a bite with little to no warning.
Although it is widely recognized by its banded body which is typically either black and pink, or black and yellow, it is not often seen as it spends up to 95% of its time in its burrow.
Here is what you need to know about the overall aggressiveness of these lizards.
Gila Monster Behavior
Since these lizards spend so much of their time in their burrows and hiding, not much is known about their exact behaviors. Here is a list of some of the behaviors that we do know about.
- Gila monsters are nocturnal, though they do sometimes come out during the day in cooler weather.
- Although they live in desert areas with very little water, Gila monsters have been known to submerge in puddles after it rains.
- Gila monsters have strong forelimbs and claws which allows them to dig through the tough, dry soil to create burrows which they live in.
- They live on the ground, but are excellent climbers, and have been spotted climbing cactus in search of bird nests.
- Mating season is in the spring months of May and June. During this time males have been observed wrestling for dominance with the winner having more opportunities to reproduce.
- Gila monsters have an extremely low metabolism, and only needs to eat a few times per year.
Gila Monster Signs Of Aggression
There is no mistaking the intent of the impressive defense display that Gila monster puts on. They may seem small at only 18-24 inches long, but they look mighty!
The inside of their mouth is jet black, and they can open their jaws wide. Facing you with their wide open black maw, the Gila will hiss menacingly, warning you to keep away.
Typically sluggish and lethargic, these lizards can whip around and strike fast if you get too close! If you do manage to get bitten, be prepared for the bite of your life!
Gila Monster Bite
When a Gila monster bites, it likes to hang on.
They don’t deliver venom through syringe like fangs like snakes do. Instead, they have to hang on and grind the venom into you as it oozes through their jaws.
They have short sharp teeth and powerful jaws which are perfect for inflicting as much pain and damage as possible. And man does it ever hurt!
While not typically lethal, the venom of these lizards causes immense pain and severe swelling that can last for over 24 hours.
Of course you have to get the lizard off of you first!
The best ways to get a Gila monster to release you from a bite is to either submerge it in water, or spray alcohol into its mouth. You should immediately seek professional medical attention if you are bitten.
Have Gila Monsters Caused Any Fatalities?
There has not been a reported death caused by a Gila monster bite since 1939.
Technically their venom is considered to be nearly twice as toxic as a diamondback rattlesnake, but they deliver such small amounts that it not lethal to a healthy person.
Most deaths prior to 1939 were either small children, or were mostly caused by the treatment itself, or infection.
In folklore, legends and myths, the Gila monster is said to be able to spit venom like a cobra, or kill with its breath. These stories are of course false.
Are Gila Monsters Aggressive As Pets?
Most keepers and breeders who have Gila monsters as pets have stated that captive bred specimens are typically docile.
Wild caught lizards are a different story, but are also illegal in most states. See our page Can You Own A Gila Monster As A Pet, for more information about that.
As with any reptile however, these lizards can be unpredictable.
You may have picked up your pet Gila monster a thousand times, but this time it feels threatened for some unknown reason and bites. These lizards can not be tamed.
You can simply learn to understand their behaviors and body language in order to prevent accidents.
If you want to learn more about them as pets, here is our Gila Monster Pet Care Guide.
Are Gila Monsters More Aggressive At Day Or At Night?
As was stated earlier, these lizards are nocturnal.
They may only emerge from their burrow several times a year to feed and mate. Day or night does not change any aggressive tendencies they may or may not have.
The main factor is whether or not they feel threatened.
They generally feel safe if given some space, but reaching for them can cause alarm. How would you feel if something 25 times larger than you was reaching towards you?
Can You Hold A Gila Monster?
You should never attempt to touch, grab or pick up a wild Gila monster.
Captive bred lizards can become somewhat accustomed to human handling. Keep in mind that these are venomous reptiles however, which are capable of delivering an extremely painful bite.
Extreme care and caution should be used, and you should never attempt to hold one unless you are very experienced at handling lizards.
Summary
The Gila monster is a fantastic and unique North American lizard.
I have known people who have lived for years in the same area where these lizards are found without ever seeing one, so be grateful if you ever have that opportunity!
Despite myths and legends about how aggressive and dangerous these reptiles are, they are really quite calm. They aren’t very nervous or skittish as long as you don’t try to pick them up, or get within a couple feet of them.