a hush of librarians, and other collective nouns

Collective nouns illustrated

via Kottke.org

I like the hush of librarians, though why are they all female? Grr*

* pet peeve, having been a male librarian for some years. Though, on further reflection, it merely shows three people dressed in female clothes. It’s entirely possible that one or more is a transvestite**
** I reckon it’s the one on the right