The Genus Fli Fly Light is an Insect Light Trap, meaning the UV light attracts flying insects and the insects are trapped on the glue board inside the unit; this is not a fly zapper. Light bulbs are generally replaced annually in the Spring for best results.
You will replace the glue board of the Genus Fli Fly Light when completely full (timing can vary depending on the level of activity).
Flylights such as the Genus Fli Fly Light are not designed to be used outside as there is too much competing light from the sun. They work best inside.