A murder of crows, a flock of geese, a herd of cattle, a pack of dogs…among many others.
Is there a name for a group of domestic cats?
Those animals have group names because they are social in nature. Domestic cats don’t normally form groups. Kind of like bears. What do you call a group of bears?
According to this site there are many collective names for cats:
http://rinkworks.com/words/collective.shtml
Among them are: clutter, pounce, and kendle.
A sloth apparently. There’s not much logic in group nouns.
Well I’ll be a monkey’s uncle. 
Occasionally, groups of female cats get together and look after each other’s kittens while one of them goes hunting. I’ve heard that refered to as a “colony” a couple of times, though I don’t know how widespread the usage is.
Hamish: you could almost call that a pride, along the lines of what lions do. Except it doesn’t have a tomcat.
I’ve seen some documentation that groups of farm cats sometimes exhibit lion-like social behavior including males taking over groups of females and killing kittens. I was originally thinking “pride”, too, based on that evidence. But somehow a “pride” of housecats just doesn’t sound right.
In the essay “Don’t give me one dozen roses, give me a nosegay” from A Passport Secretly Green Noel Perrin refers to a “clowder of cats” and “a kindle of kittens.” The essay is about group nouns, mostly from the Late Victorian era dictionary the author found.
It sounds as though Noel Perrin was borrowing from James Lipton’s An Exaltation of Larks, (or from the same sources that Lipton used).
However, clowder is simply an earlier form of the word clutter that Thin Ice posted, and (as one who has to wade through a clutter to get into bed on a cold night) I find clutter descriptive and clowder (mildly) pretentious.
Noel Perrin cites Nuttall’s Standard Dictionary of the English Language, published in London in 1887. He gives no other information about this dictionary in my edition of the book. Dunno about this Lipton guy.
(concerning bears)
Or a “sleuth” in some sources. Not that that makes any more sense. In fact, it makes less - bears can seem to be rather slothful, lying around a lot. Not much ursine work ethic in evidence.
Forced grouping as in a cageless shelter is called a colony
I’d call them a bunch. It has less pedigree than the other suggestions but it’s damned accurate.
Otherwise, just say “the cats” or “some cats”. Cats are pretty hard to pin down so a group noun shouldn’t need to be specific.
A group of cats?
@#$%&! underfoot! That’s what I usually call 'em! 
I’ve also heard “Clowder” for adult cats and “Kindle” for kittens. My source is he World Almanac.