Flora is away this week, so we’re revisiting one of our favorite episodes — about a summer visitor no one wants. Caller Jeremy has a problem: fruit flies have moved into his apartment, and he needs to know how they got there. ELT finds out where Jeremy’s freeloading flatmates came from. Guests: Biologist Marcus Stensmyr, Lund University. Chemical ecologist Kevin Cloonan, Acadia University, Nova Scotia, Canada. Thanks to Jeremy and all the listeners who shared their gnat knowledge.