This subject came up once on the list some time ago, but I thought I'd
dredge it back up and expand on it a bit.

None of the Kats have purred while in the series, although it's entirely
possible that they might do so offstage.

I read (or heard) somewhere that house cats purr when they *want*
attention, such as when they're hungry, etc.  Can you imagine *that*
applied to the Kats, like kittens mewing *and* purring when they're hungry?
Or even more fun, perhaps -- adult Kats starving, waiting for food in a
restaurant, purring perhaps involuntarily?  ;-)