Ant Mound Predation

Ant mounds, built by the Allegheny Mound Ant, Formica exsectoides, suffer a bit each year from foraging animals seeking potential food items buried in the mound.  Usually it’s just some shallow digging that does little damage to the integrity of the mound.

The animal that did this must have been more ambitious than most.  There was quite a pile of dirt brought up from this hole.

The opposite side of the mound showed an even more aggressive excavation.  I don’t know what the animal was after.  There was no evidence of anything edible in the spoil or left inside the excavation.

Crumbs from the digging are still perched atop the nearby Indian Grass stalks.  That means it was probably done last night.  Heavy rain the night before would have quickly washed this evidence away.

This explains all of the dirt piled outside the holes.  The excavation goes completely through the mound.  There was still no evidence of what motivated the animal to do this much work. 

These galleries would have been filled with ants during the summer.  In January, the ants are normally not active outside the mound, but depending on temperatures and sunlight, are often present within the mound.  I’ve read that winged queens sometimes overwinter in the colony and winged queens seem to be a treat for any animal.  Foraging animals don’t just dig for the fun of it, so I’m sure there was something worthwhile to be found here.  I just couldn’t find a clue to what it was.