Probably trying to escape actually. If you just fed him recently I'd leave him alone. I don't always agree 100% with the leave all snakes alone for a week rule, but I believe in it when a snake is showing signs of stress. Daytime roaming is always the biggest indicator that something is wrong. Usually it's my indication that my snake has gone to the bathroom and wants her tank cleaned, but she's been with me for a year and is pretty settled in.

Snakes can go a while without food. Even if she truly is hungry, waiting for her to acclimate to the new tank isn't going to starve her or do any serious damage. But feeding a stressed snake can cause a regurgitation, which is very bad for your snake.