Why do these girls always look at me?

There are these super pretty popular girls that always look at me, some that I've never even talked to. It's NEVER a mean look, always either a curious or expression-less one. Rarely, but sometimes, some talk to me and they're always nice. They always stare or look whenever they see me. It's quite strange, I've never done anything scandalous or gossip worthy and I'm not super popular, really average really. But it's not just them, it's popular guys too. What could be the reason they're staring?