Pueblans are like that. They are beautiful snakes and do very well in captivity, but they get an NI (needs improvement) as far as behavior goes. In time the biting and musking will probably stop, but the squirming may never. Hondurans are like that too to some extent. Sinaloans and Nelsons milks are much calmer as adults. Mexican milks are really calm from like 6 months on give or take.