University of Kentucky entomology professor Michael F. Potter was on Fresh Air Wednesday talking about bed bugs, the parasites that seem to be invading Ohio and Louisville.

The bedbug is sometimes called the “perfect parasite.”

“They bite you while you’re sleeping and the bites are painless,” explains entomologist Michael Potter. Potter, who works at the University of Kentucky and specializes in pest management, says there are several reasons why bedbugs are more insidious than other parasites such as lice, fleas and ticks.

“Bedbugs don’t stay on the host — they scurry away to their hidden harbors that are far from obvious,” he tells Fresh Air‘s Terry Gross. “And then on top of all of that, people react to bedbug bites differently. Some don’t react at all; others’ reactions are delayed until days or weeks later. So it’s a very efficient critter from the standpoint of doing its business and creating a lot of anxiety in terms of what’s happening.”

You can listen to the show to hear how Potter checks for bed bugs in hotel rooms, how bed bugs can infest a city and many other facts that will make sure you never sleep comfortably again.