Why aren’t cultural srats social?

Genuine question: why don’t the cultural sororities here mix with the regular ones? I’ve never even heard of them hosting or attending events or anything that might get them some recognition on campus. Their presence on campus is basically non-existent which is pretty weird because greek life is huge here. I feel like social outings are also a big component of greek life and if they’re not being social then what do their chapters spend their time doing?