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How To Sex An Iguana

Are you breeding iguana’s and want to know whether the babies are males or females?

Do you have a young iguana, but aren’t sure if you have a male or female?

When you are trying to figure out if your iguana is a boy or girl, you might ask:

How do you sex an iguana?

It is easiest to sex your iguana once they reach about a year old when males develop physical characteristics including femoral pores, fat pockets on the back of their head, longer spikes, and their hemipenal bulges will become more pronounced. If you cannot wait until the iguana is a year old, a reptile veterinarian will be able to accurately determine the gender by probing the animal’s cloacal vent.

Keep reading for more information on how to sex your iguana.

how to sex an iguana

How To Sex An Iguana

While you might be happy with your pet no matter its gender, knowing if it is a male or female will help you better care for the animal.

There are a few methods to use to sex your iguana at home, but you will have to wait until the animal reaches sexual maturity.

Sexual maturity is reached when the iguana is about a year or year and a half old.

Femoral Pores

Once the iguana reaches the age of sexual maturity, some characteristics will become more pronounced, including the femoral pores.

These pores are located on the underside of their hind legs, starting at the vent and ending at the knee.

On a male iguana, the pores will be much larger than on a female and will be very visible during the breeding season.

During the breeding season, males will develop waxy plugs growing from the pores.

He will then drag his back end as he walks, leaving behind a waxy trail on the surface to mark his territory.

While you won’t be able to see this waxy trail, other iguanas can see it very clearly.

Do not attempt to clean out or wear down the wax coming from the pores, as the male will do this on his own.

Forcibly removing the wax plugs in some cases can cause damage to your iguana.

The pores on female iguanas are not as large, and they do not have as many pores.

Fat Pockets And Longer Spikes On Their Head

Once they reach sexual maturity, males will also begin developing fat pockets on the back of their heads.

You will be able to easily see the bumps developing on the head of a male, where there are none on a female iguana.

Female iguanas will not have these fat pockets with their heads remaining smooth. 

In addition to the fat pockets, you will notice on their heads; look to the length of the spikes growing down the length of their back.

On males, the spikes will be significantly longer than those you will find on females of the same species.

In addition to being shorter, the spines are also thinner, giving you another opportunity to decide.

Hemipenal Bulges

Male members of the species will have two bulges on their underbelly located near their vent.

They are easiest to see when the iguana is on its side or back.

These are known as hemipenal bulges and are only found on males of the species.

Females will not have these bulges, and because of this, you will also be able to notice their tail tapers down almost immediately after the vent.

On males, the bulges cause the tail to be thicker and not taper off like a female’s.

Where you will notice two oval-shaped bulges on the males, you may see a single, more circular shape bulge directly above the vent on a female.


If you still aren’t sure whether you have a female or male iguana, or you want to decide before they reach sexual maturity, visit your veterinarian.

Remember to find a veterinarian who specializes in reptiles to give your pet the best care and attention.

The veterinarian will determine the sex of your pet by probing the cloacal vent.

Do not attempt to do this at home, as the veterinarian is the absolute best person to identify the sex of your iguana with this method.

If the iguana is less than a year old, this will be the only way to determine the gender.

Egg Laying

One of the best indicators of telling the gender of your iguana is if they lay eggs or not.

Females will lay eggs regardless of if she has mated with a male of her species.

It will soon become obvious you have a female iguana in your home as females are the only members of the species to lay eggs.

Other Characteristics To Look For

There are a few other signals to look at to indicate if you are the owner of a male or female iguana.

These are not definitive, but they can add another piece to the puzzle if you are attempting to decide without your vet.

Males tend to be larger have a broader body than female iguanas, who will have a more slender look.

Females will only reach lengths of 5′ feet where males can grow to lengths between 6′ and 7′ feet.

Some males might be shorter or even thinner, so this isn’t the only tool you should use to decide on the sex of your iguana.

The behavior of the animal is an indication, with males acting more aggressive during mating season.

Combine these characteristics with the others we discussed above, and you should have a good idea of the gender of your iguana.


If you determine the gender of your pet, you will be able to provide better care to the animal.

Looking at the physical characteristics of your animal or visiting a veterinarian will help you solve the mystery.

We hope you have a better understanding of how to sex your iguana after reading this article.

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