jato

1. (of birds, fish, insects) flock; school; swarm
   Jato ptica je preletelo preko reke. — A flock of birds flew over the river.
   Ronioci su videli ogromno jato riba. — The divers saw a huge school of fish.
2. (of people) crowd; bunch
   Jato novinara čekalo je ispred suda. — A crowd of reporters was waiting outside the court.

Jato covers a flock of birds and a school of fish and can also be used of insects, though for a swarm of insects roj is the usual word.