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Thw very first word to come to my mind is pack, but the more I think about it, I'd use 'gang'

The most appropriate one would be "clowder"

A gang of cats 😂🤣 great suggestion

I asked ChatGPT and "pack" wasn't even mentioned... Dunno if it's not used for Cats or if ChatGPT missed it.

I didn't know so I asked ChatGPT, there are multiple options. My favorite are "clutter" and "clowder."

Not sure if anyone will understand if I used them in a sentence, though. !LOLZ

Clowder is more appropriate word than the others.

Never saw it used in a sentence before, though.

Infestation?