How about:

A collect of priests

A surplice of choirboys (never a problem in my choir, damn, damn, damn, mutter mutter mutter)

A giggle of schoolgirls

A shriek of teenagers

A grope of Italians (sorry, but they do!!)

A flock of wallpapers

A grunt of shop assistants

A guffaw of clowns

Well, it is still early and I'm still sober, besides there are so many fireworks going off here, it sounds like the Somme!!

LTS