Where the Boys Aren't

Reproduction without sex is fairly common in the ant world, but the Mycocepurus smithii is the first known to be a male-free species. The phenomenon takes the stress out of finding a mate and may help keep the peace in colonies, the scientists believe.

And this isn't some tiny, obscure species of ant in a neglected corner of the rainforest. These little guys, er, girls run the length of South America from Panama to Argentina.