Do you know how wood ants follow their roads and can (almost) always find their way back to the nest?

When ants go somewhere they leave a track of pheromones. Other ants do nothing more than follow these tracks. There are even ants that count their footsteps. By counting the steps they know exactly how far they are from the nest!

If you want to add ants walking on your screen, then visit t http://javascript.internet.com/games/ants.html for the .js code. IE only…

See also Ant Colony Optimization algorithm (ACO) and ACO

Nest NLLI-482 is located on top of a small and old  river dune in the Zaarderheiken Woods between Floriade and Venlo. I discovered the nest in 2001, hidden under a mound of branches. Today we visited this nest, although the weather was cold and in the shadow was some unmelted snow. The old branches are now consumed by the wood ants and the nest is on a sunny slope catching sunlight.  The ants took their advantage and came out to take a sunbath. (View the movie).

The ant mounds are so constructed that the temperature inside keeps warm enough for the ants to survive the winter. In winter you can find holes inside and around these nests. They are created by woodpeckers, fouraging on wood ants. But the hole in this nest is special. However the wood ant mound shrunk a little last year, the branches prevent the top from falling down. So a little space was saved between the top of the ant nest and the top of the structure. Inside this hole we discovered tracks from an other animal. On this high-res photo you can discover all kind of material inside this nest.

What kind of animal would live inside a wood ant nest. A mice family? Or a squirrel?