Well, tugging on, stroking and mussing up the hair of my friends is something I do because I find their reactions amusing. Assuming that he isn't a close friend, and the fact that he bit your hair, well either he's a very tall two year old, or he has a hair fetish, likes you and has a weird way of flirting.
He likes you or have lust on you depends on how long you know him, touching hair is a form of showing love and affection, to me at least
He has an obvious hair fetish. It is very likely that he likes you. This kind of behavior may begin to become very creepy fast so if you don't like him doing it, make sure to say something to him.
Opinion
2Opinion
He's either trying to annoy you, or he likes you back and has a kink for hair.
He is aggravating you because he likes you
Most Helpful Opinions