Bug is a 2006 psychological horror film directed by William Friedkin and written by Tracy Letts, based on Letts' 1996 play of the same name. It stars Ashley Judd, Michael Shannon, Lynn Collins, Brían F. O'Byrne, and Harry Connick Jr., with Shannon reprising the role he originated in the play's premiere, and which he had performed over three different runs between 1996 and 2005.
The film, mostly set within a single Oklahoma motel room, follows a woman (Judd) who becomes involved with a recently discharged soldier (Shannon) who is convinced that the two are being watched by the U.S. government, who infested their room with bugs.
The film debuted at the 2006 Cannes Film Festival before being purchased by Lionsgate, who released the film the following year in May 2007. Bug received mixed to positive reviews from critics, who praised its intensity, directing, acting, and take on paranoia, but were polarized about its writing, in particular regarding the ending. Friedkin and Letts similarly collaborated again on the 2011 film Killer Joe.