Swarm Cluster

You command rats, insects, parasites or other unsavory creatures to converge at at one creature within range, eating through anything in the immediate area. Make a ranged spell attack against the target. On a hit, the target takes 1d10 piercing damage. Hit or miss, the rats swarm around the target. It and each creature within 5 feet of it must succeed on a Dexterity saving throw or take 2d6 piercing damage.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the secondary swarm damage increases by 1d6 for each slot level above 1st.