ABCNEWS.com : Parasitic Ants Shake Up Colony Society

ABCNEWS.com : Parasitic Ants Shake Up Colony Society: "Herbers is dean of Ohio State's College of Biological Sciences, and she is one of the country's leading ant experts, so she's not often stumped when she peers inside the usually violent parasitic relationship between slave-maker ants and their hosts. But that changed a few months ago when one of her researchers, Chris Johnson, returned to the lab with an acorn she had picked up in a city park.

The acorn had tiny ants, each about the size of the tip of a ball point pen, and Johnson put them under a microscope for a closer look at a 'really weird looking queen,' Herbers recalls.

''I went over there and looked at it and said 'Oh my god, you've got minutissimus.''

Leptothorax minutissimus had only been found in four other areas of North America, and the species has baffled biologists ever since it was discovered in 1942 in Washington, D.C. The species has evolved to the point that it no longer has worker ants that forage for food and carry out other chores.

'It has lost the worker class,' Herbers says. Only queens are left.

So to survive, the ants must invade another colony and take up residence as parasites. Herbers wants to find out how they do that without bloodshed. That's a very different lifestyle from the 'slave maker' ants she has studied for so long."