Why don't they want to be in your group? Are you shy/quiet and they've misjudged your intelligence? Or did you do something to make them not like you?

I hate working in groups with girls. I was in a male dominated major so I could give them attitude, and they'd get over it - and the job would get done.

Each one of those girls individually is just a person with their own insecurities. They bunch up like that because it makes them feel less weak.
If it were me, I'd imagine myself giving them some attitude. Picture yourself facing them individually. They're just people.