Many of he places where I go hiking are home to large ant mounds. These are red, biting ants about half a centimeter long, some of them larger.

The mounds are as much as three meters across, perhaps five centimeters deep at the middle, with the entrance to the colony at the center of the mound where it is deepest. The mounds consist of pebbles four to five millimeters in size that are astonishingly consistent throughout the mound.

I think I read somewhere that these pebbles are created by the ants, who use their mandibles to break up rocks underground into these small pebbles which are carried out of the colony and dropped outside, thus creating the mound.

When I told this to others on the hike today I met with disbelief. Am I wrong about this? Does anyone have a link that supports my assertion?

tanstaafl.

And no photo?

These ones perhaps (no mention of how the mound is created)?
http://en.wikipedia.org/wiki/Red_harvester_ant

Dunno about the pebbles, but the ants sound like fire ants, ubiquitous in Texas, and seriously annoying if you should accidentally step in their way.

My Dad, as a young man, used to go out in the Wyoming country with a gem hunting neighbor. One of the places to find small gems was in ant mounds. The ants would bring them up with all the other small stones. The trick was to burn out the mound before trying to scoop up it up for later sorting.

OK, here you go. It took a while before I was back up in that part of the mountains to take these.

The following post has the first picture at full resolution.

tanstaafl.

Attached is the full-resolution photo. Not especially good, but in my defense, the lighting was hard to deal with.

tanstaafl.