Controls house flies without any insecticide. These traps are ready to use, moisture resistant, non-toxic and pesticide free. Each box contains 4 clear sticky traps. Attracts and traps flying insects! The Indoor Fly Trap is a transparent strip of sticky paper that contains glue with a natural attractant. The patented âLâ shape design keeps dead flies in the trap and glue off your windows. Flies are the most common pests around homes. The Indoor Fly Trap catches all types of flies that invade homes, such as house flies, cluster flies, blow flies, little house flies and garbage flies. These flies become attracted to light from windows, and can easily be captured.