Conjure Scavengers

You summon 2d4 Swarms of Ravens that appear in unoccupied spaces that you can see within range. Roll initiative for the summoned creatures as a group, which has its own turns.

The Swarms attack whichever creature within 50 feet of them has the lowest amount of hit points, even if that creature is you or one of your allies. If there are no creatures within 50 feet of a Swarm, the Swarm moves towards the closest creature that it can see. If a Swarm sees no creatures nearby, it flies off to search for prey elsewhere. If any of the Swarms hit a creature that is already at 0 hit points, that creature suffers two failed death saving throws instead of one.

The Swarms ignore constructs and other Swarms of Ravens.
The DM has the creatures' statistics.

At Higher Levels
When you cast this spell using a spell slot of 4th level or higher, the amount of Swarms you summon increases by 1d4 for each slot level above 3rd.