As the saying goes, “Don’t bite bed bugs.”

Recent studies reveal that these pests have been accompanying humans since they ventured out of caves approximately 60,000 years ago, possibly earning the title of “the first true urban pest.”

Researchers indicate that understanding the symbiotic relationship between bed bugs and blood-sucking parasites could enhance predictive models for the spread of pests and diseases as urban populations swell. This finding was detailed in a study published in the journal Biology Letters on Wednesday.

Through genetic analysis, Virginia Tech researchers have found that the populations of bed bugs that fed on humans began to dwindle until the last ice age around 20,000 years ago.

At this point, the two lineages began to diverge.

“The most thrilling part is the resurgence of human-associated strains and a rise in effective population,” stated Lindsay Miles, the study’s lead author and a postdoctoral researcher in the Department of Entomology at Virginia Tech. News Release from Wednesday.

Bed bug populations also surged approximately 12,000 years ago when humans began forming large settlements that evolved into cities like Mesopotamia. The study noted that furniture and blood-sucking pests such as rats and cockroaches became domestic nuisances.

The research indicated a decline in the bat bedbug.

The analysis of demographic patterns “offers compelling evidence that human-associated lineages closely followed the demographic history and movement of modern humans toward the first city,” concluded the researchers.

“Bed bugs shared living spaces with early humans, and as humans migrated, they took along a subset of the population, leading to reduced genetic diversity in those strains associated with humans,” explained Warren Booth, an associate professor of urban entomology at Virginia Tech.

The team observes an “effective population size,” which refers to the number of breeders contributing to the next generation, allowing them to glimpse past trends, according to Miles.

The earliest human civilizations emerged around 10,000 years ago, creating optimal conditions for the “proliferation of pests in communal cities,” as noted by Miles and Booth in the study results.