a division in greek life?

I see sorority ladies of all organizations walk around campus, eat together, work out at the gym and sit in class together.

But when it comes to fraternities Delta Chis sit with Delta Chis, Kappa Sigmas work out with Kappa Sigmas, Sigma Chi sit with Sigma Chis and so on.

Well do people in IFC all get along with each other or do they just stick with their own people?