To put this lightly and nicely, chameleons down like us , they tolerate and trust us.By not harming and hand feeding and just being around your cham you build trust as in it sees that the big scary human won't hurt them and you bring food. Crawling onto your arm simply means they now see you as a safe zone and as a way out of the cage. This can be accomplished by hand feeding, cup feeding, and free ranging. Look into all of those and he/she will one day come through and will trust you enough to come and venture out of its cage. Now this is not guaranteed because it also depends on the chameleon temper. They are all different. I did all this with my veiled and if I so much as get near him he wants to bite me, my panther tolerates me and will not be on defense ever only if I bother. Hope this helps.