This is a "field ant" nest, although the photo doesn't do it justice. They have infested my yard since last year and I can't get rid of them. I've got some nests that are 8 feet wide; there's at least 5 all together.

The stuff I've read says their nests only get to 2 feet wide. They must really like my yard! It looks like they bring up sand and stuff from the nether worlds and pile it all on top of the grass. Again the scientists say this ain't so. Where does it come from then?

They must have lots of tunnels under the sand because the ground is nearly hollow underneath the sand. You don't want to step in one of the hollow spots - the little buggers bite.

It's war!