Drill Infestation

3 Stones in the shape of drills form, and are fired into a number of creatures equal to the number of drills. for each drill fired, make a ranged spell attack. Each drill deal 1d8 piercing damage. Upon a hit, the drill(s) then burrow into the creature's body. As an action you can cause the drills to do an additional 1d4 damage per drill within the creature. Another drill is created for this spell for each level casted above 2nd.