He has his favorite hide (http://www.reptile-food-direct.co.uk...tile_cave.html) and he also has a half log in there. His attitude has been consistent the last few months that we've had him (curious but shy with sudden movements). We upgraded him to a large rat recently (his previous owner fed medium).
If he attacked my partner and I (who live in the room with our rats), it would be one thing, but he lunged at Sam, who smells like...teenage boy.
We'll try to work with him if there's nothing else we can do, but thanks for the questions.