Verminous Tide

You summon a writhing mass of plague-ridden rats to swarm over an area. Choose a 10-foot radius within range. The area becomes difficult terrain and any creature that starts its turn there must make a Dexterity saving throw or take 3d8 piercing damage as the rats bite and scratch. On a failed save, the creature must also make a Constitution saving throw, becoming poisoned for 1 minute on a failure. The creature can repeat this save at the end of each of its turns.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the radius increases by 5 feet, and the damage increases by 1d8 for every two slot levels above 3rd.