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Foresters are set to log the ancient Holystone Forest, in Northumberland, England. But first they need to locate and save a few homes located in the forest. Are these structures human dwellings? No, they are giant ant mounds.

The northern, or hairy wood ants  (Formica lugubris) build towering mounds out of pine needles, from three to seven feet tall. The nests act as solar collectors and heaters, allowing wood ants to live in places too cold for most other ants. In addition, the large black and red workers sometimes bask in the sun to warm up and then move underground to act as living heat radiators.

wood-ant-mound
Smaller wood ant mound from Switzerland

The hairy wood ants that build the mounds are now endangered, and every effort is being to made to protect them. Naturalists located of 69 mounds, which they mapped and gave GPS coordinates. Hopefully, the maps will help the loggers avoid getting too close.

For photographs and more information, see:
Guardian.co.uk has a story: Giant ants' nests given special building protection

York Dales Country News story:  GPS used to protect ant 'skyscrapers'

For photos and more information, see BBC - Potter ponders giant anthill

Edit:  And for children, see The Ant's Nest book review at Simply Science.

Leafcutter ants are exceptional ants. They construct large, complex nests. Each colony has a number of different worker castes performing a wide variety of tasks. Everything about leafcutter ants is done on a big scale.

Leafcutter ants are named for their habit of cutting out pieces of leaves and carrying the slices back to their nest in their mandibles. Workers process the leaves, spread the resulting paste in an underground garden area, and grow a specific species of fungus on it. Rather than eating the leaves, which may contain toxins, the ants eat the fungus instead. In fact, the fungus is so critical to leafcutter ant survival that the queen ants carry a bit of fungus with them when they go on their mating flights.

This video shows leafcutter ants in action.

Let me know what you think of leafcutter ants.

While investigating the Dorymyrmex bicolor ants I posted about on Monday, I spotted a few other ants that looked similar, mostly because of their red-brown and black coloration.

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On closer observation, however,  these ants were obviously another species. First of all, they were almost double the size.

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The long hairs on the underside of their heads gave it away that these were harvester ants in the genus Pogonomyrmex. The 'beard" of hairs, called a psammophore, is characteristic of the genus. In fact, the name Pogonomymrex means “bearded one.”  Psammo comes from the word for sand in Greek, so the psammophore acts like a basket or an extra pair of hands to help the ants move sand, dirt, and probably some types of food as well.

pogo-californicus

These turned out to be a color variant of Pogonomyrmex californicus. Cole (1968) describes the species as concolorous light ferrugineous red in coastal California, moving to concolorous black or brown to the eastern part of its range in southern Texas.

Ants of the Southwest has a good page about these harvester ants that shows some of the the color variations.

It seems that Dorymyrmex bicolor and Pogonomyrmex californicus are often found in the same open, arid environments. It's interesting that at this Maricopa, AZ site their coloration is so similar.

This little ant is fairly easy to identify.

First, look for the volcano-cone-shaped nest.

cone-nest

If you spot some active ants with reddish-brown heads and alitrunks, and black gasters, take a closer look.

dorymyrmex1

If there's a cone-shaped bump on the posterior dorsal surface of the alitrunk, then you've found Dorymyrmex bicolor.

Dale Ward has some close-up photos to show the characteristics of this species.

We saw it in typical habitat, which is open and dry. In this case the were at an agricultural research station in Maricopa, Arizona.

dorymyrmex

Dorymyrmex commonly feed on nectar and honeydew. Check out the nearby guayule flowers.

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dory-on-guayule

Guayule is a plant grown for its latex, which is used as a natural rubber.

Obviously, insects find it useful too.

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