Big iguana interested in Lil one??

Question
QUESTION: I have a 3 ft long iguana named Lester and I my daughter has an iguana that is about 1 1/2 ft long named Iggy. Ok my question is, when I let Lester out for his roaming time he seems to always make his way to Iggy's cage and stare at her through the glass. Is this because he is being nosy or you think maybe he wants to see her more? We do let them see one another once in a while, but I would love for them to be out at the same time. I just find it curious why he always ends up laying next to her cage watching her.

ANSWER: Hi Larriann,
First, are you sure that Lester is a "he" and Iggy is a "she"?  
If they are both males, it can be an "just letting you know who is boss" attitude.
If they are male and female, introducing them on neutral ground can work when there is plenty of room for each of them to claim as their own space, if needed. There is quite the size difference so caution needs to be taken there.  
With Males, they think all females want to be bred..which is one of those things that we prefer not to happen. Even though females can and do lay eggs without being bred(we freeze those eggs), and Iggy is way to small yet to produce eggs.  
If Lester decides that he is in breeding mode, and with Iggy being smaller and not breeding time, Lester can do harm to her with bites and scratches.
Igs will take an interest in other igs, and it can be tough to figure out if it is good interest, breeding interest or.."I want to beat you up" interest.
If there is gentle head bobbing going on, its most likely a good interest. If you do decide to allow them out together, be prepared to remove one ASAP if you see any slight problem arise.  This may come in the form of side to side head movement, posturing(standing up on all fours) or puffing up...and also flared dewlap.
Many people have had success with free roaming a male and a female or two females....it all depends on each igs attitude.

---------- FOLLOW-UP ----------

QUESTION: Actually I dont know, I was told by the previous owner Lester was a male and everything I have read points that way. We have assumed Iggy is a female. There is no head Bobbing. Let me tell you what happened lastnight and see what this means also. My 6 yr old found Lesters key to his cage, and well he must have awoke lastnight at some point and snuck by my room, anyways he put Iggy in Lesters cage. Which we have not even attempted, they have there own space. But when I came down this morning Iggy was in Lesters basking area and Lester was on the bottom of the cage with his nose in the corner laying there. Not really sure what that meant. I tool Iggy out of the cage right away. Lester seems fine now. But was curious why He was in the corner like that? and how can we tell if Iggy is a male or female?

Answer
Hi Larriann,
In the signature line under my name, there is a link to my webshots pages..there are folders of my igs there. You can see the pores and other info pics as to sexing the igs.
Not all males do head bobbing, and a lot, if not all females will headbob...
As you see, its not always the bigger of the two that can be the boss!!  It sounds like Iggy put Lester in his place. it sounds like Lester surrendered to Iggy taking over his basking spot.