sometimes you can't! The only thing to do is watch his urate(the white part of his pee) which should be white, not orange. Orange means he is not getting enough water. Some chameleons do not drink infront of people as weird as it sounds. If you are concerned about that, you can always run a dripper. Honestly, my chameleon rarely drinks from mistings and I rely on the dripper for hydration. Is he eating? you just got him and he may not eat or drink for the first few days cause he is getting used to everything.
