(CNN)Bedbugs roamed the earth with dinosaurs but the tiny blood-sucking pests likely didn't bother T. rexes and their kin, scientists say.
New research has found that bedbugs have been around for more than 100 million years -- much longer than previously thought.
"To think that the pests that live in our beds ...were walking the earth side by side with dinosaurs, was a revelation," said Professor Mike Siva-Jothy from the University of Sheffield's Department of Animal and Plant Sciences.
Siva-Jothy, who co-authored the research published Thursday in the journal Current Biology, said that bedbugs had been assumed to have come into existence about 50 million years ago, around the same time as bats -- their first animal host.
But the 15-year study looking at the DNA of 34 species of bedbugs found the creatures evolved about 50 million years earlier than bats.
"The assumption was that they evolved on bats, which evolved about 40 million years ago, so they're about twice as old as we suspected they would be and they evolved on an ancestor that we have no idea what it was. That was the first big surprise," said Siva-Jothy.
The scientists said more research was needed to find out exactly what animal bedbugs would have fed on but they ruled out the blood of dinosaurs because "bed bugs and all their relatives feed on animals that have a 'home' - such as a bird's nest, an owl's burrow, a bat's roost or a human's bed - a mode of life that dinosaurs don't seem to have adopted," according to a statement from the University about the study.
How the team made their discoveries sounds like something out of an Indiana Jones movie.
Klaus Reinhardt, a co-author and professor of applied zoology at TU Dresden University in Germany told CNN that finding the different bedbug species was physically demanding work.
"To get these species we couldn't rely on museum specimens because the DNA was degraded," he said.
"So we went into caves in South East Asia, we went to caves in Texas, in Mexico, in South America," said Reinhardt.
"We climbed walls, and we climbed church towers."