From what you've described- teasing, staring at you, smiling, etc. It certainly sounds as though he likes you!
However... It can be dangerous to take these things for granted, because if the attention he's giving you suddenly stops, or he starts doing the same thing to other girls, you leave yourself open to getting hurt.
My advice - if you really like him (and suspect he feels the same) talk to him about it. You don't have ask him out right away if you don't feel comfortable (although if I were you, I'd say you probably have nothing to lose by doing that!), but try to lead the conversation to a place that gives him the opportunity to tell you how he feels.
If he is shy, or doesn't realise that you like him, he might not be ready to make a move, so give him a bit of a push! If he doesn't feel the same, it's really no big deal. It might be a little awkward between you for a few days, but it'll pass real quick, and then, at least you'll know. Wondering what someone is thinking can drive you mad! I'd always much rather know for sure.