St. Valentine Blood Bath!

African weaver ants (so-called for their ability to build nests of leaves bound with the ants, silk) maintain the largest territories in the invertebrate world. From elaborate treetop citadels, a colony of up to half a million individuals can deploy its forces over six square miles. To feed such a colony, says entomologist Janusz Wojtusiak of the Zoological Museum in Krakow, Poland, the ants, each about three-tenths of an inch long, prey on relatively large insects as well as on birds, lizards, frogs, snakes, and even bats.Their modus operandi - death by stretching - involves many worker ants pulling on the victim in a lethal tug-of-war, culminating in the arduous trek up a tree with quarry in tow. How, Wojtusiak wondered, do the ants haul prey hundreds of times their size? (The ant shown here, for example, holds a bird weighing about a quarter of an ounce.) The answer, he and his colleagues found, was in the ants, feet. An electron microscope revealed powerful suction pads, or arolia, between their tarsal claws. "Arolia have been seen in other ant species," Wojtusiak says; they enable ants to walk on smooth tropical leaves. "But weavers must have incredibly strong adhesive abilities."