Your new dorm room might be freshly vacuumed; the door is probably decorated with a nametag that your RA stayed up all night to make. Sure, it looks welcoming. But that doesn't mean it's pristine, or even clean. And it definitely doesn't mean your new home sweet home is all yours.
The best time to wage war on an intrusion is before it even starts. As soon as you arrive in your new room, you should look carefully for any signs of a bug or rodent infestation. You'll be able to see everything without any obstructions, and if there are any problems, they can be taken care of before bugs get a chance to nest in your stuff.
Damage to a window or screen can give refuge to any number of insects, while mice might have enjoyed the opportunity to frolic around campus undetected. So closely check windowsills, lighting fixtures, closets, baseboards and even the edges of carpeting -- while some creatures are obvious, others might be more difficult to see.
Now is also the best time to look for bedbugs. These disgusting little creeps can actually survive without feeding (shudder!) for several months, so contrary to popular belief, they can easily survive a summer without human prey. Look carefully around the seams of your mattress and in any cracks in your bed frame. If you see them, it'll be a lot easier to kill them before you unpack your bedding and make the bed. (Also check the perimeter of the room along the floorboards, and any other soft or upholstered furniture.)
All clear? Then it's time to open your suitcase and give your teddy bear some fresh air.