I've always been amused at the collective nouns that the English language applies to grouping of different sorts of animals. Alligators and their cousins, crocodiles, aren't the only ones to gather in congregations; so, oddly, do plovers (a shore bird). Some are merely curiosities, reflecting the nature of the critters themselves (a charm of hummingbirds) or some sort of onomatopoeia (a zeal of zebras). Others strike me as some sort of human commentary (a congress of baboons really does speak to our current political times). There seems to be no real sense to many others, but it's fun to check them out; you'll find long lists on the Internet.