He was pretty tame from the get go, but he started doing that about a month after I got him when he got used to me. I got lucky too, he's been picky about eating since it got real hot out so it's been anybody's guess as to whether he'll eat on any given night lately. I noticed he was more aggressive as soon as he saw the F/T mouse rather than after a few minutes of checking it out, so I usually try to "lure" him out of the viv with the mouse so he'll bite it out of reaction. Last week he got it while he was still in the viv, and I didn't want to risk him dropping it and not eating if I tried to take him out, so I left him eat it in there. The problem is, I use aspen bedding. Fortunately, he didn't mind resting his head on my hands while he ate...lol