Ants with opposable thumbs?

Well, o.k., they’re spines, or even tarsi. But they function much as do our vaunted opposable thumbs. University of South Florida biologist Deby Cassill and colleagues report that ants use short, thick tarsal spines on their forelimbs to pick up and manipulate objects. Until now, researchers believed ants did that sort of thing only with their jaws, or mandibles, which they use for, among other things, plundering rival colonies, snatching up their prey, and carrying prey, or rival ants, back to the nest where … well, you don’t want to know. In fact, two thirds of an ant’s head are given over to the muscles that run the mandibles.

But the USF researchers have now filmed ants using the spines on their forelegs to grasp and maneuver embryonic eggs and larva. “Thus,” they write, the ant “joins a short list of animals known to use their forelimbs to manipulate ojbects including insects such as the mantids, Crustaceans such as the crabs and lobsters … and veterberates such as the pandas, koalas, opossums, rodents and primates.”

And the best news here? The ant species in which the research team discovered this rare ability is Solenopsis invicta. That would be the fire ant, an invasive species that has overrun the American South and is already well-known for … thumbing its nose at human attempts to control it.

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For further information, here’s the source:

(http://www.springerlink.com/content/a08132x3718p236p/). Cassill, D.L.,
Anthony Greco, Rajesh Silwal and Xuefeng Wang. 2006. Opposable spines
facilitate fine and gross object manipulation in fire ants.
Naturwissenschaften