Lasius niger or the common black ant is one of nature's most abundant clean up crews. Who hasn't come across an ant hill or nest in their yard at some point. Each nest holding usually 3000 to 4,000 workers. The first thing most people do when they discover ants is to run to the store to purchase poisons to kill the nest. Of course for the avid gardener or the lawn enthusiast they can be quite a problem.
Ants can also be beneficial. They find and drag back to the nest the dead (and some not so dead) bugs that they discover on our property. This ant spent two hours dragging this dead june bug across my driveway to the lawn.
This ant found a dead moth on a different section of driveway and with the help of some of its fellows soon had carried it off. The ant hill itself is a massive series of tunnels that aerate the soil and resolve the compaction of the ground. Thus they do provide benefits to mother earth. Unless the hill threatens to become very tall I don't do much about the ones in the lawn. I draw the line when they enter the house.