but how to collect a human?

Collective nouns.

(Yes, these are real. My favorites are bolded.)

• A shrewdness of apes.
• A flange of baboons.
• A cete of badgers.
• A parcel of birds. A pod of birds (small flock). A volary of birds (in an aviary).
• A dissimulation of birds.
• An obstinancy of buffalo.
• A rabble of butterflies.
• A clowder of cats. A clutter. A comfort. A chowder.
• A coalition of cheetahs.
• A quiver of cobras.
• A muster of crows. A hover. A parcel. A murder. A horde. A parliament.
• A pitying of turtle doves.
• A seething of eels.
• A charm of finches.
• A stand of flamingoes. A flamboyance of flamingoes.
• A skulk of foxes.
• A kindergarten of giraffes. A journey. A kaleidoscope.
• A troubling of goldfish.
• A remuda of horses.
• A cackle of hyenas.
• A husk of jackrabbits.
• A brood, smuck, or smack of jellyfish.
• A troop of kangaroos.
• A kendle of kittens.
• A loveliness of ladybirds.
• A leap of leopards.
• A steam of minnows.
• A business of mongooses.
• A pandemonium of parrots.
• A covey of partridges.