How to tell if a guy likes you from afar?

[Anonymous]

There’s this guy who i don’t know very well. We work at the same place but not really together as he is in a different department to me, though our work does cause us to cross paths on occasion.
I’m not sure, but i have a feeling he might like me, or be interested in me at least.
I’ve noticed him, he is attractive, and i want to know if i am right in thinking he might have noticed me too.

What are some ways guys would behave or show they are attracted to a girl they dont know well? What if he were shy?

[slatyb]

Have you spoken to him? Do you know his name? Invite him to lunch or whatever.

[spartan55]

Have you said hello to him? The staring thing is a waste of time.