Cage Aggressiveness

Question
My girlfriend and I have a 4-month-old iggy (SVL: 3.5", TL: 12.5") that we've had since the middle of July.  He's in a 18x18x24" Exo-Terra cage, with multiple heat lights (75w screw-in and 35w Halogen), and UVA and UVB (Exo-Terra 15" 5.0 and 2.0) bulbs too.  We keep the humidity around 65-70% and the heat at the bottom is around 82-83 degrees F, with the basking spot ranging from 92 to 97 F.  He enjoys a good diet of collard and mustard greens, with carrots, watermelon, and blueberries (loves those) every now and again.  A few times a week, we sprinkle some supplemental nutrition on his food that he eats without incident.  When out of his cage, he's very inquisitive, loves exploring, and is usually easy to handle so we can move him either to another part of the room, just to hold him, or to put him back in his cage.  He's normally very tame and we've even had him sleep on our arms, legs, and stomachs without the need to hold him in place.

Our problem has to do with his cage.  When he's in there, he is very difficult to get, usually running circles around all parts of the cage in an attempt to evade us.  He is even aggressive the moment he is put back in.  He could have been sleeping on my arm a minute before and as soon as he gets his front two limbs onto a branch, he gets aggressive, dropping his dewlap, arching his back, and tightening his tail in preparation for whipping.  Sometimes he'll stay on that branch or vine for 5 or 10 minutes after being placed back in the cage eying us wearily, and sometimes he'll immediately run as far from the doors as possible.  While both attempting to get him and put him back in his cage, we move very slowly and call out to him in soft tones.

I am in the process of building a much larger habitat for him (8x7x4 feet) that should hopefully be ready in a few weeks.  Can you please tell us what his issue might be?  Thank you.

Answer
Hi Sam,
Glad to hear you are working on a new habitat!! Your iguana will love you for it!!
The issue your ig is having is this... he is being a normal, juvenile iguana.  They act like they forget who you are and feel they need to run away.  They also tend to think that they need to protect their space from these humans that are invading!!  You never know(in their minds) when this human creature is going to try and make a meal of them!
In most cases they do eventually outgrow that craziness for the most part.  I have an 8 yr old that goes crazy like than every now and then.
You just continue to do as you are doing and then one day, he will just crawl on your arm like he never acting like a lunatic.
Do try to allow him to climb on you instead of trying to pick him up.  Sometimes that helps.  One of the problems with a small cage is that you are always above him and to him, you are a huge bird trying to grab him up.  When you do get his new cage done, a word of caution...make sure that his basking shelf is not higher than your eyes.. you don't want him to be higher than you when you have to get him, or do other things.  He will think he is alpha if allowed to be higher than you....eye level is the best.