Bedbugs have a long history, all the way back to the dinosaur age, a new study says.
British researchers said bedbugs evolved more than 100 million years ago and were around when dinosaurs were in charge.
"To think that the pests that live in our beds today evolved more than 100 million years ago and were walking the Earth side by side with dinosaurs, was a revelation," said researcher Mike Siva-Jothy. He's a professor of animal and plant sciences at the University of Sheffield.
"It shows that the evolutionary history of bedbugs is far more complex than we previously thought," Siva-Jothy said in a university news release.
He and his colleagues compared the DNA of dozens of bedbug species worldwide in order to learn more about the evolution of the little bloodsuckers that can plague our living spaces.
One major surprise was that bedbugs are about 50 million years older than bats, previously believed to be bedbugs' first hosts.
The researchers also found that a new species of bedbug makes humans their host about every half-million years. Also, when bedbugs changed hosts, they didn't always become specialized on that new host, but rather maintained the ability to jump back to their original host.
This shows that some remain generalists that can move from host to host, according to the study. The results are in the May 16 issue of Current Biology.
Another discovery was that two major bedbug pests of humans -- the common and the tropical bedbug -- are much older than humans. This challenges the theory that the evolution of ancient humans caused other human parasites to split into new species.
"These findings will help us better understand how bedbugs evolved the traits that make them effective pests -- and that will also help us find new ways of controlling them," Siva-Jothy said.
And even though bedbugs were around during the time of the dinosaurs, it's unlikely they fed on them. The researchers said bedbugs feed on animals that have a "home," such as a bird's nest, a bat's roost, or a person's bed. Dinosaurs don't seem to have had such behavior.
But it's unknown which animals were bedbug hosts during the age of the dinosaurs.
The U.S. Centers for Disease Control and Prevention has more on bedbugs.