Swarms, Rats, and Rat Swarms

I am looking for rules on swarms -- large numbers of very small creatures. My memory tells me there are rules for rat swarms somewhere, but I cannot remember where.

I do have the Rat King from Sub Rosa 18.

Thrice-Told Tales, box on p. 120

Then you also have the box on Swarms, p. 99 of the same issue of Sub Rosa (#18), in Mark Shirley's excellent article on natural animals - this should be the same as the rules refered above I'd think, as mr Shirley authored both.

Yay! Thank you!