Today was feeding day and as my ribbon snake gets really hyper after eating, I hung out and watched him explore for a while. He was coming out from under his hollowed log, and was staring at me as he often does, when suddenly he opened his mouth as wide as he could! His mouth looked four times the size it is when it's shut, and I could see his fangs and several other little teeth. He kept it open for a second or two, and it looked like his upper jaw was spread out like his lower one. Have any of your snakes ever done this? Should I be worried?