Last night, actress Mary Louise Parker was on Late Show with David Letterman, revealing that she's been worrying about that feared scourge, bedbugs. But Letterman didn't seem very convinced they were a real threat, asking, "Is it that treacherous? Is it that dire?... What's the worst that can happen if you have bedbugs?" Oh, Dave, if you only knew!

Letterman wondered if they burrowed into people's skin, like ticks, and Parker explained, "They don't burrow into your body but they burrow into your life." Because her son has some bites on his arm, she hired a company to inspect her home—more specifically, a dog named "Bugsy" sniffed around (if he smells the bedbugs, he sits down). Letterman continued to question her level of concern about the critters, since they're so tiny after all, and was incredulous when Parker explained that bedbugs scurry away—"Isn't that cockroaches? You're describing cockroach behavior" and later admitting, "I wish I cared more about this," launching into his experience being bitten by a tick ("I had a 103 degree temperature...it injects parasites into your bloodstream and the parasites devour your white blood cells").