Sounds like your husbandry is spot on. I agree that he is likely looking for food. A small mouse isn't enough. Prey should be 10 - 15 % of the snake's body weight. My young ones take F/T rat pups easily. I feed every 5 days until a year old and then move to every 7 days.

The 10 gallon will be big enough temporarily, but he will need more space soon.