Do cornsnakes ever become violent towards their owners?

I opened my snakes cage to pet it, but when I touched him he slithered away rapidly underneatht the wood shavings and his water dish and when i tried to touch him again he began moving his tail rappidly back and forth like a rattlesnake. .. I'm scared he's going to bite me. . .. I'm really freaked out. . . He's never acted this way before, and he's been acting a little strange all week, but not like this. I fed him on saturday. He started acting this way a little bit after I placed his cage underneath the window so he could recieve real sunlight. Any ideas of what's wrong or what I should do?