"Field Trip" is the twenty-first episode of the sixth season of the science fiction television series The X-Files. It premiered on the Fox network on May 9, 1999, in the United States and Canada, and subsequently aired in the United Kingdom on Sky1 on July 18. The episode was written by John Shiban and Vince Gilligan, from a story by Frank Spotnitz, and was directed by Kim Manners. The episode is a "Monster-of-the-Week" story, unconnected to the series' wider mythology. "Field Trip" earned a Nielsen household rating of 9.5, being watched by 15.40 million people in its initial broadcast. The episode received largely positive reviews from television critics.