Flies Invading Arizona Homes: 3 Entry Points and How to Stop Them

Flies are more than an annoyance — they are a genuine health hazard. House flies (Musca domestica) land on garbage, animal waste, and decaying matter, then walk across your food preparation surfaces, transferring pathogens including Salmonella, E. coli, and Shigella. Drain flies breed in the organic slime inside your drains and can indicate a plumbing problem. Fruit flies breed in overripe fruit, fermented liquids, and the residue inside recycling bins. In Arizona's warm climate, fly populations can explode rapidly — a single female house fly can produce up to 500 eggs in her lifetime, and eggs hatch in as little as 12 hours in summer heat.

Flies enter Arizona homes through three main pathways. First: gaps around doors and windows. Even a 1/16-inch gap under a door is enough for a house fly to enter. Inspect all door sweeps, window screens, and weatherstripping — replace anything that is torn, bent, or missing. Second: drains and plumbing. Drain flies breed inside the organic biofilm that coats the inside of slow or clogged drains. If you see small, moth-like flies near your bathroom or kitchen sink, your drain is the source. Clean drains with an enzyme-based drain cleaner and fix any slow drains. Third: gaps around utility penetrations. Pipes, conduit, and cables that enter through walls often have gaps that flies and other pests use as entry points. Seal these with expanding foam or caulk.

Eliminating flies requires addressing the breeding source — not just killing the adults you see. For house flies, remove garbage frequently, keep outdoor bins tightly sealed, and clean up pet waste daily. For fruit flies, eliminate all overripe fruit, clean recycling bins, and check for forgotten produce. For drain flies, treat drains with enzyme cleaner weekly. If fly populations persist despite these measures, professional treatment can identify breeding sources you may have missed and apply residual treatments to entry points. Pest Control Bros serves Maricopa, Chandler, Casa Grande, Tempe, Gilbert, and Mesa — contact us for a free inspection.