What should I do about girls I hang out with being really rude to little kids?

This might be a little bit long but I'll make it as short as possible. At lunch and recess I hang out with this group of girls. We hang out in this particular spot all the time. But sometimes these little kids sit there and these girls go up to them and start being really rude. They say things like 'Beat it, this is our spot and has been since like forever!' And now they are being plain stupid and putting up signs saying 'No little kids allowed. Trespers will be prosecuted!' They have now been talking about telling on to the teacher the little kids and getting them in trouble just because the kids happen to sit on a couple of seats that these girls don't even own. I don't really want to point out to them how stupid this all is because if I do I won't be able to sit with them at lunch and in cles and I literally don't have anyone else to sit with.