Fly Control & Extermination Solutions
The problem with zappers is that the flies can’t see them in the bright sunlight outside in the daytime and the flies are not active at night. I would try a strategy of using Disposable Fly Traps between you and that dumpster. In addition, I would use some MaxForce Fly Spot Bait on an as-needed basis. It can be mixed with water and sprayed on trees fences and buildings to make it available to the flies but keep it out of the reach of pets and kids. That plan should give you some pretty good control.
These flies described are cluster flies and they became a problem for you in the fall; only you didn’t know it then. They cluster up on the outside of the home in the fall especially on the south and west exposure where the sun has warmed the brick and wood. As the weather cools they crawl deeper into cracks and crevices and end up inside the walls and in the attic where they lay dormant until spring. Now they are trying to get outside but they are confused and lost and accidentally end up inside. The time to deal with them is in the fall before they get in. At this point you can spray some Stryker 54 or CB 80 Aerosol into the air to kill them. Remember to spray the south and west sides of the house with D-Fense SC in September or October to prevent them from getting in.
Small Flies-Fruit Fly, Phorid Fly, Moth Fly, Sphaerocerid Fly, Fungus Gnats and Cheese Skippers
Many small flies(1/4") are found in food prep areas and may
carry disease-causing organisms.
The six fly species listed below are the most common of small flies.
Nuisance and Biting Flies-Cluster Fly, Face Fly, Stable Fly and Mosquitoes
Many commonly found flies found around the home are a nuisance and or bite. As with many flies, these flies breed on decaying organic matter and animal wastes. They may transmit bacteria and viruses to humans. Flies such as stable flies or horse flies (sometimes called " biting flies ") feed on mammalian blood and give a painful bite.
Sanitation and identification of the type of fly you are battling are crucial steps to eliminating them.