Vacuum cleaners kill fleas just as well as any poison, surprised U.S. researchers found. They said a standard vacuum cleaner abuses the fleas so much it kills 96 percent of adult fleas and 100 percent of younger fleas. Glen Needham, associate professor of entomology at Ohio State University, suggested that the vacuum brushes wear away a waxy outer layer on insects called the cuticle. Without it, the fleas, larvae and pupae probably dry up and die, he said. The findings were so surprising that the researchers ran their experiment several times.