Bed bugs are more than just a modern nuisance. New research shows they have been with us since humans first started living in caves around 60,000 years ago. That makes them possibly the earliest household pests in human history.
The study, published in Biology Letters, examined the genetic history of two kinds of bed bugs. One lived on bats, and he other followed humans. Both populations shrank during the last Ice Age, but only the human-adapted bugs recovered.
As humans began to evolve and form permanent settlements around 12,000 years ago, bed bugs found the perfect environment to thrive. Their population grew along with the rise of early cities like Mesopotamia. That timeline makes them older pests than even rats or cockroaches in domestic spaces.
“There were bed bugs living in the caves with these humans, and when they moved out, they took a subset of the population with them,” said Warren Booth, a co-author of the study and an associate professor of urban entomology at Virginia Tech. This explains why the human-following bugs show less genetic variety than their bat-associated relatives.
Researchers focused on “effective population size,” a term that refers to the number of individuals contributing to future generations. This data helped the team track how bed bug populations rose and fell alongside human history. The bugs that chose humans adapted well and are now found all over the world.
Lead author Lindsay Miles said the research offers a clearer view of how pests have evolved in close step with us. It also raises questions about other animals that may have made similar transitions from wild to urban living.
Today, bed bugs live in furniture, walls, and bedding, feeding on human blood. They remain hard to eliminate and easy to spread. Their long relationship with humans shows how difficult it can be to fully escape a pest once it has adapted to life at our side.
