I just got a new Dum baby male last weekend at the reptile show here in Kansas City. He was very calm the first day. Then the next day he was a bit nippy. He has been burrowing in his Aspen as well. He would not eat his frozen thawed mouse. I tried on two separate nights. I just had him out again this morning. He is a feisty little bugger! He was jumpy and tried to strike me several times and even hissed at me once. We named him Rorschach, which now seems appropriate with his bad attitude, hehe! Everyone I have talked to, says they mellow and calm with age. It sounds as if this truly is the norm for these guys.