You're watching Animal Planet and the camera zooms in on five lions lazing in the sun. You think, hey, a pride of lions.
In the distance, you notice wildebeest, hundreds of them ... a whole herd.
You glance at the aquarium next to your TV and notice that, as usual, your six neon tetras are moving together in a school.
Then your pack of four Yorkies jumps up on the couch with you, searching for the cheese puffs they know you've dropped.
Pride, herd, school, pack; these are words that describe bunches of the same animal. Easy.
But what would you call, say, seventeen otters?