When Mulder is being tested by Kritschgau for psychic abilities, Mulder jokingly asks "Who ya gonna call?" The test is similar to the one performed on a co-ed in Ghostbusters (1984) by Bill Murray's character Dr. Venkman. Michael Ensign, who appears in this episode as Dr. Barnes, is the hotel manager in Ghostbusters.
The 50,000 dead crickets that littered Scully's tent were rented from a local entomologist. The smell proved overpowering for the cast and crew.
This episode posits the theory that aliens were involved in the planet's previous extinctions - the so-called ancient astronauts theory.
This is the most watched episode of the seventh season.
Chris Carter wrote this episode at the same time David Duchovny was working on The Sixth Extinction II: Amor Fati (1999).