They are testing you man. Women respond to negative actions, right? So do guys. We just don't like to see it.

Alls I'm saying is that if she bitches at you, bitch right back. And then get into a conversation with her, and get her number. (You don't really have to).

Honestly, I dare you, give this a try.

"(Girl bitches while you were looking at her)"
"Hey, I was just noticing that girl over there is hotter than you."