Tuesday, January 5, 2010

Cracked Ant Mounds

As winter approaches, the ants close their surface tunnels and seal the mound. This helps to moderate temperature changes and shed water from the wintering ants below. Foraging animals sometimes open a winter mound, but this year there has been a widespread threat to the integrity of the ant mounds.

The rapid temperature change on New Year’s Eve caused a quick freeze of the wet mounds. The surface of the mound froze into a crust and then was cracked as the soil beneath froze and expanded. The crack will allow snow melt and rain water to enter the mound instead of running off.

Each mound formed its own unique pattern of cracks. Most had a moderate amount of damage, like this one here. Small mounds didn’t suffer. Probably because they didn’t have enough material left inside after the outer shell formed.

A few sustained massive damage. Wide cracks with deep crevasses covered the surface.

I don’t know enough about what goes on within a wintering ant colony to predict what effects the damage may have. I’ve seen this type of damage occur before and the numbers of ant mounds keeps increasing, so maybe I’m placing too much importance on maintaining a tight cover over the colony.

1 comment:

  1. ...you'll have to keep us posted this spring. That last mound looks really big. 3-4 feet in diameter and a couple of feet high?