When a handful ruin it for the rest...

I have been having the problem a lot lately where a handful of students, maybe 5-7 or so, just will not stop talking. It's too many students to ignore and it's too many students to re-distribute throughout the room. I end up having to wait and wait for them all to quiet down. In the meantime, the other kids start going stir-crazy and getting chatty again. (Or they get really frustrated that the others won't quiet down, and start crying.) I can't figure out what to do about it. I recognize that we are at about week 7, and that's usually when my campers start evolving into non-listening chatter-boxes as well. So, it's not entirely unexpected. It's just that I can't figure out what to do about it. It frustrates me because it's just not fair to the 5 kids who quiet down right away every time, and it's not fair to the 10 kids who quiet down fairly quickly after that. And it's not fair to the 5 kids who want to quiet down, but can't because they are being talked to and don't know how to ignore it.