Kind of had the same situation over here not long ago only it was with frickin' corn snakes!

Pipes froze up and we had to call a plumber to repair one of the broken lines. He was hear for a good hour and a half. After all was done he asked what we kept in all the tanks. We told him corn snakes and freaked out! Said that if he had known that from the beginning he would've never worked on our pipes. Obviously nothing happened. None of my snakes were out and all locked up and secure(besides, what is a corn snake going to do to you?!)but he's already made it known that he will not work in our house again.