What do call a group of caterpillars

Here's a page I had to bookmark.

The Ask the Experts page of Ask Oxford (a bit redundant, wasn't it?). Anyway, this page in particular has a list of collective terms used to refer to groups of animals.

Handy, isn't it?

So it goes that you would say

A sute of bloodhounds,
An army of caterpillars
A fling of dunlins
A business of ferrets
A drove of hogs
A watch of nightingales

And many more.