haunt mostly concrete
They hurt humans by using power drills to make excruciating sounds. In some cases, they also manage to drill into power cable, water mains, gas lines and other essential building services.
The only way to dispel them is by way of a large check. Once cast out, they will wander aimlessly until they find another nice building to invade.
There is also a Drill Demon Lord that uses compressed air jackhammers in addition to the usual drill, and a much smaller Familiar Drill Demonlet, that usually has a much smaller drill, likes to torture wood, and is only active on weekends.
Unfortunately, while the Drill Demon Lord is sensitive to dispelment by check, there is no known way of getting rid of the Familiar Drill Demonlet, short of cutting off the power, which of course angers the Wake-up Clock Gnome and the Disk Sync Dryad.