Once you’ve raised your pair of chameleons to adult size, you’re ready for the introduction phase. I usually take the female and place her gently into the male’s enclosure, but in my experience it also works vice-versa. The theory is that if you place the female into the male’s territory, he’ll be more aggressive and will want to show his dominance by breeding her.
Monitor the female closely. The next several seconds tell you everything you need to know about whether mating will take place. Mating will only be successful if she’s ovulating, and it’s not something that’s always visually apparent. The only real way to tell if she’s receptive is to focus on her reaction to the male.
The male will immediately take notice of her and will most likely start moving towards her. If she’s not receptive, she’ll either quickly try to run away from the male, or she’ll start gaping (hissing with mouth open) towards him, or both. If she’s receptive, she’ll walk slowly, and will seemingly not pay much attention to the male’s advances. She’ll then allow mating, which takes anywhere from 5-30 minutes.
If she’s not receptive, remove her immediately because she could get injured by the male, and try again in a few days. If she is receptive, allow the chameleons to breed for 30 minutes or so. If you want to be thorough, leave them together for 24 hours and then remove the female.