If this is the first time that you will be taking care of an iguana, then it is probably best to acquaint yourself with the biology and basic behaviors of an iguana, so you will know if there is something wrong with your new pet reptile. 

The first thing that you have to know about iguanas is that they are reptiles and, therefore, they need a constant source of heat and UV rays to stay healthy. Iguanas will not be able to function in habitat with a temperature that is less than 79 degrees Fahrenheit. 

UV rays are also necessary so it the iguana will be able to metabolize calcium and other minerals. Without UV rays, your iguana will probably suffer from bone mineral disorders that often cause the death of these magnificent reptiles. 

Anatomy 

Just like other reptiles, your iguana has a pair of eyes for scanning the environment for food and potential predators. It has a pair of ears that are protected by a fairly wide portion of skin called the subtympanic shield. 

The iguana also forms spines along its back  these pliable spines are called the caudal spines and, over time, these also grow long and hard. Iguanas also have a flap of skin under their lower jaw called the dewlap.

Iguanas are herbivorous (they feed on plants only), so they are equipped with very small, yet very sharp, teeth that are designed to tear apart fibrous plant matter. 

Be careful when bringing your hand near the iguana`s mouth, because those teeth can cause serious tears in your skin. If you look closely at the top of the iguana`s head, you will notice a prominent, light patch of scale. 

This is called the parietal eye, or third eye. The iguana uses its third eye to detect changes in light in a given area. Fun With Life believes that this primordial eye is also used to detect flying predators, so the iguana can make a run for it before becoming some other animal`s lunch or dinner. 

Reptilian body language  

Iguanas can feel threatened fairly easily, and if you don`t observe its body language closely enough you can get bitten or hit by its massive tail. Unlike dogs and cats, iguanas will not vocalize a lot before biting, so be careful especially if the iguana you have has not been tamed yet. 

The dewlap, or the large wad of skin under the iguana`s jowls, is also used to communicate. In the wild, an iguana may raise its head to extend the dewlap to signal a simple "hello" to members of its own species. 

An extended dewlap may also mean that it is trying to protect its territory from the human owner or from other iguanas. During mating season an extended dewlap may mean "I want to mate" (this only applies if there are female iguanas in the same enclosure, and it`s mating season). 

If your iguana has been tamed, and is used to your presence, an extended dewlap may mean that it is a little drafty and it is trying to make itself feel warmer. 

Here are some other body language signals that you may want to memorize: 

  1. Bobbing head - "I`m the big man around here" 
  2. Bobbing head (to owner) - "Hello!" 
  3. Bobbing head (fast) - "I`m threatened and I`m ready to fight" 
  4. Bobbing head (fast, side to side then up and down) - "I`m threatened do not go near me!" 
  5. Flicking tongue - "Just exploring the air. Possibly eating something." 
  6. Flicking tongue - "I`m about to take a bite out of something." 
  7. Sneezing - "I`m purging my system of something." 
  8. Whipping tail - "I`m about to attack." 
  9. Squirming - "I do not like being held." 
  10. Head and front legs stretching - "I feel good and I feel happy!"