Flies are often annoying and uninvited guests in our homes that can easily contaminate food and spread disease. We often encounter a variety of flies in a typical household throughout the year. They are fast breeders and if left unchecked can establish large populations quickly. Bug & Fly Clear Window Traps will help you control nuisance flies and control fly populations. We recommend changing out your fly strip ever 30 - 45 days. NOTE: If the traps are kept in a location where there are extreme temperature ranges they tend not to last as long in the field