Monthly Archives: April 2010

When we are not doing experiments, my son and I have been reading Animal Architects: Building and the Evolution of Intelligence by James R. Gould and Carol Grant Gould. animal-architects

We have enjoyed the book so far. It is not an easy read, but the stories of the different animals are fascinating. The book is much more than a review of animal construction techniques, it is how different behaviors reflect an animal's cognitive abilities. It also reveals how researchers interested in cognition measure an animal's potential.

The only point that has disappointed us has been the relatively thin coverage of ant architecture. Aside from a brief overview of the nests of army and weaver ants, the Goulds pretty much skip the ants, giving the excuse that what ants do is mostly underground and hard to study.

If you are interested in animal architecture, there are ant nests that do deserve attention. Take a look, for example, at this leafcutter ant nest. It definitely rivals that of the fungus-growing termites in its complexity and size.

Another excellent example of elaborate engineering by ants is found in Holldobler and Wilson's Superorganism book on pages 338-339. Harpegnathus saltator ants build a nest that comes complete with "wallpaper," and is thought to withstand flooding that occurs during the monsoon season.

Ants are also capable of making decisions about potential new nests sites, a similar issue that faces honey bees when swarming. The nest emigrations of tiny acorn ants of the genus Temnothorax have been studied extensively. Evidence suggests that scout ants investigating potential new nest sites actually have a way to "measure" the interior of a cavity to determine if it is suitable.

Here's an example experimental set up:

temnothorax

And finally, check out Alex Wild's wonderful photographs of examples of ant architecture.

What do you think? Are ants capable of intricate architecture?

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toothbrush

This week my son and I have been watching a toothbrush. No, we haven't gone bonkers. This does have something to do with ants.

You see, we saw this post about an unusual Ant-traction. It seems that a certain type of ant likes the rubbery buttons Colgate toothbrushes. Go check it out. Here's a link to the original post, as well.

The first thing we wondered, of course, was whether this is a prank or hoax. I think you could get the same effect by rubbing a little sugar water or honey on the brush.

We bought a toothbrush to check it out. So far our fire ants, Solenopsis xyloni, could care less about the toothbrush. But that doesn't mean the effect isn't real. It could be that the rubbery bit contains a pheromone specific to one or a few closely-related species of ants. We are going to continue our experiments.

If there turns out to be something to this, it won't be the first time humans have inadvertently produced a product that mimics an insect pheromone. One classic example is the finding that termites of the species Reticulotermes flavipes will follow an ink trail drawn by a certain type of pen. (See for example, this experiment).

If you'd like to learn more, here is a video showing EO Wilson explaining some of the basics of pheromones and other chemical signals in ants:

We'll let you know if we get any ants to react.
And please let us know if you try this experiment, what your results were, and what kinds of ants you used.