I've got a mature Dumerils boa (about 5 years old)...she's a very docile snake. She typically likes to burrow under her substrate rather than sit in one of her hides all day. When I reach in the tank to let her know I'm there, maybe thinking about picking her up, I usually lightly pet/stroke her...lately she's been tensing up when I do that and if I do it for more than 10 seconds straight she will run into her hide. I don't recall her being THIS timid but I've only had her a couple months. Does this sound like stress or is this pretty typical snake behavior? She used to be way more open to being touched but seems extra timid lately...