Hardly a Speck of a Fly, But Able to Decapitate Ants Scientists have discovered the world's smallest known fly: a tiny, parasitic native of Thailand that appears to decapitate its host ants. "Here's something barely visible to the naked eye and it has wings, eyes and complete organ systems," said the insect's discoverer, Brian V. Brown, curator of entomology at the Natural History Museum of Los Angeles County. The fly, Euryplatea nanaknihali, is less than two-hundredths of an inch long - one-fifteenth the size of a housefly and one-fifth that of a fruit fly. It was collected as part of the Thailand Inventory Group for Entomological Research, a project involving more than 100 scientists around the world. Dr. Brown describes it in the July issue of Annals of the Entomological Society of America. Like a larger African relative, the fly seems to lay its eggs in the heads of ants. The larvae then feed from the head's muscle tissue; eventually the ant dies and its head falls off, whereupon the fly pupates and leaves the ant's body. Dr. Brown said the study was one more example of the importance of small creatures in the ecosystem. Insects in particular provide invaluable services like pollination and decomposition - and, in this case, ant control. "People are so obsessed with dinosaurs and elephants," he said, "they forget that the small things are out there."