When people ask me how I tamed a big lizard, the explanation I reach for is simple. Trust.
A wild animal that trusts you will not be afraid of you. If its not afraid of you, its aggression will vanish. Aside from injuries, and over the top feeding responses its pretty safe to attribute all reptile aggression to fear. This article does not address animals with aggressive feeding responses but rather aggression that isn't food related.
Sadly, the common thought and even advice that people have received is to tame a monitor or iguana you should take it out of its cage and HANDLE IT. Handle it handle it handle it. Not only should you handle it, you should handle it TONS, the more the better.
I won't say this doesn't work for some animals and in certain circumstances, the second I say that, people will be shouting the opposite. But what is safe to say is
handling backfires and flat out doesn't work on most of the highstrung animals people purchase. I know this because I've been there when people give up the animals they had high hopes for because it wont tame down or even becomes more aggressive than before. There are also a number of animals that start tame and become aggressive due to interaction with the handler.
There are two main reasons "handling" will not tame your aggressive lizard.
Firstly,
most people are going to become increasingly frightened or wary of their pet as this goes on. This will unconciously affect your body language, how you grip the animal, how you hold it etc..
Generally the turning moment were you will not "win" and theres a downward spiral is when the animal bites you. People who get bitten immediately drop the animal, put it away, or otherwise disengage it.
The lizard has learned that you will ignore all his other warnings and that he must bite you to make you go away. Once the animal learns that biting works he will resort to it faster each time you handle him. In fact he may abandon all his other warnings and just nail you right away on the very next try. Monitors in particular are very intelligent for a lizard and I've personally witnessed two trial learning occur on multiple occasions. Its important to prevent bites but extra important to try to not react much when it bites you. You don't want it to learn that biting "works". At the same time you should recognize that its time to put the animal away, just don't drop it like its hot so to speak. You want a few moments to pass before you set it down if possible.
The bitten owner will no doubt ably be nervous during the next handling session (lizard bites are extremely painful), OR completely give up, often giving the animal away.
The second reason "handling" will not tame your aggressive lizard
An animal that is struggling, running away, defecating on you, biting you, tail whipping, etc etc is very very
frightened. When you interact with him and he does these things, he builds the association that you are SCARY. You are not to be trusted, you will do scary, uncomfortable things to him. Each time he sees you there is already that bad history there.
You wouldn't tame a feral cat by picking it up and hugging it everyday would you? How about a tiger? Its the same concept. The animal is terrified and is likely not going to submit to you. He's wild and undomesticated, hes not thinking, hes just going on instinct, and instinct says that big animals (you) that grab him and restrain him are going to eat him.
Another commonly overlooked portion of the handling paradigm is that the animal is removed from the cage for the "taming". The lizard goes from small, comforting, familiar surroundings and sure footing to a huge room with moving floor (your hands) often 4ft off the ground if the person is standing.
Reptiles find small spaces comforting, and big spaces scary. Baby animals get eaten if they blow their cover. Baby monitors hide, brave juveniles and ADULTS walk around. They know they aren't food.
I am of the opinion that
an Iguana or Monitor should NEVER be forcibly removed (aka, picked up) from their enclosure while they are gaining your trust unless its absolutely necessary. Their cage is to become their Home base or safe spot and they will climb out on their own or even better, onto you, when they trust you.
Front opening cages are best for taming lizards. The top openings of aquariums require you to hover over the animal which is threatening for them. When you slide open a screen top, to their eyes, the whole sky just moved and a monster appeared. Its better to have glass doors in the FRONT that you can open as little or as much as possible.
Desensitization, hand feeding and BAT.
Firstly, its important to let your lizard simply acclimate and have a strong desire to eat before attempting any training. New homes are stress full to any lizard and many monitors and iguanas are wild harvested. They need to settle in first and for most.
BAT (behavior adjustment training) was developed with dogs and horses but work very well on reptiles in my experience. You just have to tweak it a bit. Instead of the lizard walking away from the scary thing, you are going to walk away from the lizard.
BAT is part about pressure and part about rewarding appropriate responses. This is the first step I use when working with an aggressive animal. Followed by hand feeding and eventually lifting.
You are going to place your hand in the cage with the animal (putting pressure on). First as a fist, and eventually as an open hand. The fist is very important in the early stages so no fingers get bitten. I prefer to show the animal the back of my hand if they are to the side of me or the top of my hand if they are directly in front. We want it to look like too big of an object to bite if it comes to that accidentally.
In this exercise the removal of your hand is the reward for good behavior.(taking pressure off)
Place your hand just barely inside the cage. The animal needs to see you do this. If it doesn't react, remove your hand from the cage. After a few seconds repeat. Hand needs to completely disappear between repetitions. Do 5-10 of these exercises then end the session.
If the animal reacts slightly to your hand being in the cage (puff up are the most common) just rest it there for a few seconds to see if the animal will settle. The moment they calm down, remove your hand.
If your lizard panics you will have to start slower and have your hand near the glass but not actually in the cage. If your lizard completely looses it, abort the session and try again the following day with more distance.
For VERY aggressive animals you will have to walk towards the cage and then away when they don't react. You leaving is the reward for being calm. Wait for moments of loose body language, coming towards you in curiosity, eye pinning or even licking your hand. These are all things you should reward.
As the animal progresses you should begin to talk to it to accustom it to human noises. This is a trigger for some lizards so it should be worked on.
As you progress you should vary the locations of your hand, adding different heights, motions, duration etc. All these things need to be added slowly.
If your animal panics or gets aggressive, you've moved too fast and should go back a step. They will learn faster if you go slower. Every time you frighten them you are straining the trust you just gained. GO SLOW. You will have this animal for ten years or more if its young.
There is no hurry.
"Hand" feeding is the quickest way to get your lizard to interact with you if its not otherwise aggressive or as the next step after you have done BAT. If you are taming a monitor, I recommend teaching a bowl as a hot spot. Think of it as a vending machine. The monitor learns that food appears only in the bowl, which makes it a valuable training tool. The monitor will associate food with the bowl and not with your hand. Contrary to popular belief its ok to have the monitor associate you with food. You simply must add the extra structure to it to prevent being bitten. I do not like tongs or tweezer for this because they mirror the motions of our hands and that may confuse the animal in the early stages. I do believe tweezers are a valuable tool but not for this instance.
Start by feeding in the bowl for a few days to build the association. The bowl needs to be small or medium sizes and easy to manipulate. If the monitor will come up to the bowl with you present place
one insect (or mouse) in the bowl and then place in the cage in front of the lizard. If using pinkies be sure to keep your fingers as tucked in as possible to prevent a feeding mistake.
Let the Monitor eat their morsel and remove the bowl completely from site. Then immediately repeat. Do this as many times as the animal will let you for several feedings. Be sure to place the bowl in different spots to make it clear that the bowl produces the food, not the "left side of the cage" or "on this one branch" etc.
The goal here is to create a bowl hot spot so the animal will not be looking for food in other places. This is also desensitization because you are repeatedly putting your hands in the cage and then removing them.
For iguanas, if the animal has shown to be a bitter in the past, use the bowl method as described above, for all others feeding from the fingers is OK. I find that many fearful iguanas will refuse to hand feed on their normal food. They certainly have a hierarchy of favorite foods. Flowers (hibiscus, nasturtium etc) and fruit will generally convince the iguana to feed from your fingers when normal greens fail. Experiment with different foods to find your "high value" treat for training.
When you are hand feeding your iguana,
its important that the animal has to take at least one step to get to the offered food. Iguanas have a tendancy to "glue" themselves to a spot once they calm down and you want to prevent this. If you place the food in its face, it will likely panic, as you have come into its space too closely or it will simply learn to "glue" down and not come to you. Having to take a step towards you and then feed reinforces that walking towards you is the right thing to do. As this progresses, you will want to have the animal walk further and further to get its reward, culminating in feeding on the edge of the cage.
This is where the first actual lifting should begin. Place your finger or hand on the animals chest for just moment. Do this a few times. If they object, go back a step. If they don't mind, start using pressure (as if to lift but
don't actually lift) for just a second or two at a time. You will likely have to distract with food during this first session. Don't push it, end the session while your ahead.
Superman! Time to fly
This is where counterconditioning comes in. You are going to begin to "levitate" or float your pet for brief moments about an inch off the ground, then immediately feed/reward them. I introduce a clicker at this point because of the obvious delay between being lifted, set back down and then fed.
Monitors and iguanas learn what a clicker is in two trials, so there is no need to load the clicker, just use it. I lift, click, then set the animal back down and present the reward (the hotspot bowl).
Lather rinse repeat. You will need to work on height and duration SEPARATELY. If you add height, decrease duration and visa versa. If they begin to get frightened, end the session, TBH though, by this point I've never had an animal spook out. They do not leave the cage at all during this part of the training. The safety of the cage is working with you still.
Time to come explore!
When its time for the animal to start exploring outside their cage its important that they know how to get back to home base. As the animal trusts you more and more it will begin to ask to come out of its cage. Its important that the lizard is conditioned to being lifted and "levitated" for brief distances by this point because its your job to put them back in before they panic. Your lizard will have a pattern at this point;
Walk up to cage door and ask to come out.
Walk out of cage onto you or a surface
See something scary, be it a thing or another person OR they realize they are to far from home base for comfort.
Become overwhelmed and panic. Running at random, if your lucky they'll run back to their cage.
Its your job to put the lizard back BEFORE it spooks and freaks out. If you put the lizard back before it panics it will generally immediately try to climb back out again. This is good. Let it come out again, about the same distance, then put them back again. You'll find you can't get rid of them, they just come right back at you. This repeated in and out will desensitize the animal to the room at large. Its getting exposed to the same thing, over and over at low levels and learning that nothing bad is going to happen. Its also learning that it'd rather be with you than in that boring ol' cage.
Your Monitor or Iguana is going to be TOO BRAVE and then quickly turn into TERRIFIED during its first trips out of the cage.
Its your job to curb their enthusiasm so no one gets hurt. If you think they can handle 6 inches, let them come out 2inches three or four times then end the session. This is also good practice for being carried and riding on you. They are like little kids that just can't help themselves. Be the parent.
You can introduce food at this point if you so choose, to reward brave (but not too brave!) behavior outside the cage. Make sure to use your bowl hot spot if you are feeding a monitor.
As time goes on you can add more and more freedom. If you want to carry your lizard, wait until they are acclimated to the room and then practice walking around in the room for several days at minimum before moving on to other parts of the house. A harness is a good idea for going outside.
In my experience, if people follow the above protocol you can have an aggressive iguana or monitor tame in aprox 30 days. There will be variation of course, but don't expect an overnight magic wand . Trust takes time! Be slow and methodical and you wont regret it. You will have a better pet, and your lizard a better life!
