How effective are electric fly zappers in controlling flying insects indoors and outdoors?

Electric fly zappers can be effective in controlling flying insects both indoors and outdoors. They work by attracting insects with a light source and then electrocuting them when they come into contact with the zapper. However, their effectiveness can vary depending on factors such as placement, size of the area, and the type of insects present. It is important to use them in conjunction with other pest control methods for best results.