These Girls keep on looking at me, what does this mean?

[Profoundstew247]

Alright, so there's a bunch of girls at my school who are preettty attractive and by a bunch i mean a group that hangs out together. I'm friends with them but not really close friends. I usually dm them on twitter now and then and our conversations last for about 4-5 hours. Anyway, at school in, one of them sometimes brings out their phone just to look at me sometimes or when i'm listening to the teacher actually stares at me until I look back, then she smiles/giggles and looks away. Another one ( the one which I probably like the most) basically stares at me and if I look back, she looks away as fast as she can or just carries on staring until I look away. The rest do the same thing really. Do they want attention or something? Don't really know and I want to make a move on one of them buuut I don't really wanna be shut down, so I kinda want the assurance first