If it was a live mouse, I guess thats why you don't leave them alone, cause you never know. I have never heard that, weird.
As far as having a mean burm, Let me tell you a story. My burm used to hiss at me everytime I went to move her in her cage or take her out. I am told and have learned it is mostly a bluff. Once out she did not hiss. When she was 4ft, I took her out and had her around my arm and my girlfriend was sitting there on the couch, and I started goofing around,singing Brittnay Spears and I moved my arm fast and I heard this hiss and next thing I know I have four red dots on my hand, I got tagged. She used to snap at the glass when I walked by all the time. This is when she was not eating or eating live. Well I have read several posts and have learned this much. Your snake might not be snapping because its mean but because one it smells food. They are very aggressive when it comes to eating. Mine now, when I walk in the room with the rabbit to let it unfreeze is already wagging her tail for it. She does that, its funny wags her tail. When I first got her I did not know this about burms or snakes that they can smell that food and there normal reaction is to strike at whatever moves. I though I was going to have to get rid of her. Because of the aggression But I smartened up and I worked with her and as she has grown, and is not eating she is very calm and great ( I am not saying yours is like mine but and Idea). The second thing is the snake is scared. When they are defensive they will strike its one of the things it does. Mine did that and then let out that smell, and that was awful when she bit me, the smell killed me. Keep working with her. Gradually do things with her. For months all I did was sit on the couch with me, not really moving. she would move and I would have to move her but she did not like things in front of her head, I had to go under the head. I am finally at the point I will walk around with her on my shoulders. Next step is people in the room, more than just me and the girlfriend, but never trust your snake, you can have confidence in them but never trust them.
Good luck
