REDTOP Flycatchers is intended for outdoor use only. With over 80 million sold in 32 countries, this often copied fly trap device is a necessity to rid your home and property of flies. The easy to read and simple instructions will show you how to get your trap set up and see results within a few short days. Just remove the REDTOP lid, straighten out the mesh cone, add the bait and some water and hang it outside your home. Flies breed outdoors and NOT in the home, the REDTOP is designed to draw flies away from- rather than into – the home. 85% of flies caught in this trap are egg-laying females. By controlling the females, the entire fly population is brought under control. Each trap can hold close to 10,000 flies. It is highly effective, non-toxic, ozone safe, hygienic, and very easy to use.