Noun. A work condition where numerous people are working on the same thing (i.e. a car or a house. Generally, anthills only refer to physical things like cars and houses, not a project for school/work/etc), resembling ants on their hill. Can be helpful to completing the project, or can impede progress by having too many people doing too few things.
While working on a client's car, we had much to do, so we called in a couple guys who had the day off. A productive anthill resulted, which allowed us to get the car done ahead of schedule.