I have not tried hornworms, yet. I just can't spend that much for a "treat"! But I do use hand feeding as a positive reinforcement for my cham. Since beginning this, he has begun to trust me much more, and will willingly come out of his cage now (He has even sat on the door a couple of times, and climbed out as soon as the door was opened.) and is quite happy to perch on my shoulder, or top of my head. I have even had him refuse to go back into his cage! This is pretty amazing for a male veiled around 1 year old, but it's true! I also think it helps that his cage is right in our living room/kitchen doorway. He sees us walking through constantly, and that includes our daughter (3 1/2) and our dog, too. So he's quite used to seeing us and our movement. He doesn't act as though he is stressed at all, and is quite active. And he has been happy to come out for a while, every day this week. (insert criticism here...I know it's coming!) But, I think there is something to be said for the trust of these lizards. I feel as though if I were to put him into a quiet/low traffic room, he would be much less trusting of us, and completely unwilling to interact. Maybe this is just the individuality of the animal, and maybe not, but I don't think I would change a thing for him. He is happy, and we are happy. And he feels secure enough to trust us enough that we won't hurt him, and that we are not a threat.