Scientists at the University of Arkansas at Fayetteville and Texas A&M are studying the DNA of the flightless insect famous for infesting bed mattresses and pestering people as they try to get a good night's sleep.

Arkansas entomology professor C. Dayton Steelman, who collects laboratory samples, says bedbugs hide during the day but come out at night to feast in breeder houses where hens lay eggs for hatcheries.

"They're usually in there by the thousands, maybe even millions, before they're detected," he says.

The scientists believe the breeder houses are "geographic epicenters" from which the bugs migrant to other parts of the country by traveling poultry workers and by other birds, such as swallows that nest in the houses.

James Austin, a scientist at Texas A&M, says the spread of rapid transit and global travel also most likely have helped bedbugs multiply.