Fly Killers for Restaurant Kitchens at Brennan Catering Supplies.Keep flying pests away from the kitchen with this selection of fly killers and fly screens. The best way to keep your fly problem down to a minimum is to have both these items working together.The first line of defence against flying insects is a chain door fly screen. This is ideal for busy kitchens, allowing easy access for staff as they don't need to use their hands. Although the screen makes it difficult for flies to pass through, any that manage it will be disposed of hygienically when met with a commercial insect killer.