Nation diary: a nest busy with housekeeping ants | Bugs


HWhen I was standing so close to the wood ant nest on one of the warm days of last spring, some aggressive defenders climbed on my pants and bit me. Their arched nest, which is thatched with Sitka spruce needles, extends over two meters on the bank along the forest path. Had it been a hot summer afternoon today, the seething crowd of workers on its summit would have looked like boiling black volcanic lava trickling down the slope as they forage for food.

But this morning – cold and wet again – only a few dozen residents are scattered across the surface, busy with the household. An opportunity to see the amazing instinctive social organization of these predatory ants introduced to control needle insect pests.

The sanitation of the colonies seems to be a priority today, with several bringing out their dead. Dragging rigid, stiff-legged corpses across the uneven surface is tedious work, so most choose to bond the jaws to their dead comrades and eventually toss them away from the nest. Other workers carry what appear to be tiny silk duvets in their jaws that must be cocoons from recently hatched adults.

A wood ant nest next to the forest path that is covered with Sitka spruce needles and houses 100,000 ants. Photo: Phil Gates

How are these tasks distributed? Are there specialized ant undertakers or are there any workers who instinctively pull injuries? Is the newly hatched first job to dispose of the cocoons that kept them warm during development? The anthill’s social responsibility is a mystery.

What is certain, however, is that a new generation is hatching. This ant metropolis will be home to at least 100,000 people by midsummer, and deep in the underground galleries and chambers, several queens will incessantly lay more eggs.

I can see a couple of winged males walking around on the surface. Newcomers from another nest looking for a queen to impregnate? Or newly hatched males about to disperse to another colony? I can’t dwell long to find out. A defense attorney has climbed onto my dangling camera strap and, standing on his hind legs, squirts formic acid from the tip of the belly on me. Time to let her do her housework.

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