Another symbolic sound is the hum of a mosquito. Although his producer insists that these parasites don't live in Los Angeles (since "mosquitos breed in swamps; this is a desert"), its distinctive sound is heard clearly as Barton watches a bug circle overhead in his hotel room. Later, he arrives at meetings with mosquito bites on his face. The insect also figures prominently into the revelation of Audrey's death; Barton slaps a mosquito feeding on her corpse and suddenly realizes she has been murdered. The high pitch of the mosquito's hum is echoed in the high strings used for the film's score. During filming, the Coens were contacted by an animal rights group who expressed concern about how mosquitoes would be treated.