How to Get Rid of Drain Flies in a Restaurant

Drain flies is a term sometimes used collectively to refer to all small flies that can breed in drains such as true drain flies, phorid flies, and fruit flies. In this article we will focus on true drain flies. With their moth-like appearance, drain flies may not inspire immediate concern in a commercial kitchen like roaches or rats, but do not ignore their presence. As a restaurant, hotel, food truck, or other kitchen run for commercial purposes, the general public is relying upon your vigilance to remain healthy. As you know from your training and experience in your kitchen, you have a high duty to the public to ensure good safety practices and cleanliness.

Drain flies, sometimes called a moth fly, are small flies that are hairy or fuzzy like a moth. These nuisance flies are usually found resting on walls or ceilings, but their mere presence indicates a breeding site is nearby. Drain fly breeding sites are problematic in your commercial kitchen because it shows things are not being cleaned as thoroughly as they should be.

Drain flies lay their eggs in the slime and gunk that accumulates in drains and other wet areas. Anywhere that holds water can be the drain fly breeding ground. Moist, slimy, decaying organic matter and gelatinous film that forms over the water, is ideal for drain flies to lay their eggs. Drain flies really like breeding in sewage. Sink and floor drains in restaurants are the most common source of the drain fly larvae, but do not overlook drain pans under the refrigerator, around or inside of garbage containers, wet sewers or leaky toilets, condensate lines for ice makers, and even under a leaking washing machine. Drain flies have been known to propagate in a water and organic matter than accumulates under a broken or loose tile.

Drain Flies and Kitchen Health and Safety

Drain flies do not bite humans, but can spread diseases related to contact with fecal matter such as E.coli. For example, if drain flies are breeding in sewage they may pick up E.coli bacteria and then land on a food prep surface or a soda fountain spreading the bacteria to food and beverages. In addition, a knowledgeable health inspector will know to give you an extra thorough inspection if they notice a drain fly on the wall. Because accumulations of food bits, grease, and grime are required for their presence, it may indicate that roaches and other pests have easy access to food in your commercial kitchen.

As a restaurant or other commercial kitchen, you must take every precaution to prevent pests from becoming established. Proactive procedures should be followed to regularly clean drains, pipes, underneath and behind appliances and food prep areas. Allowing these areas of moist organic matter to fester, not only breeds drain flies, but more insidious insect pests as well.

How to Get Rid of Drain Flies

Despite your best and most efficient efforts to keep your commercial kitchen spick-and-span, drain flies can overrun even the tidiest of kitchens. The most important factor in getting rid of drain flies is determining where they are breeding. Drain flies are poor fliers; the adults usually remain close to the area in which they hatched, grew as larvae, and pupated. However, in a commercial kitchen with many sinks, floor drains, disposals, garbage cans, there are many potential breeding locations. Your drain fly infestation could be emanating from one drain or multiple locations. If you are unsure where the drain flies are breeding, test various drains by inverting plastic cups lined with adhesive or a light coating of petroleum jelly. If the drain is actively infested, after a few days you should capture adults as they emerge from the drain. By isolating the areas of activity, your control efforts will be more efficient.

The only way to get rid of drain flies is to disrupt and eliminate the drain fly nursery. Drain fly larvae are pretty hardy considering their tiny worm-like appearance. Ineffective attempts at control include pouring boing water, ammonia, bleach, or baking soda and vinegar down the drain. Remarkably, drain fly larvae can survive all of these attacks. Drain fly larvae have the unique ability to trap air bubbles and remain submerged for about 24 hours. In your attempts to remove the drain fly scourge, do NOT pour insecticides down the drain. It is likely illegal, and it will NOT kill the drain fly larvae.

To truly halt the drain fly life cycle, you have to actually get into the drain and scrub it clean. This not only physically removes the immature drain flies, but also removes the food source for any future drain fly. Once the drain is free of the gelatinous rotting matter, the larvae will not succeed. To adequately clean the drain, it should be opened as much as possible and aggressively scrubbed with a long handled stiff wire brush. Make sure to scrub all crevices, grooves, bends, and threading of connections.

Professional Drain Fly Control For Your Restaurant

Drain fly control should be a part of any pest control program initiated in your restaurant. Once the drain is thoroughly clean, your pest management professional can place bacterial drain treatment in the areas that tend to accumulate gunk. These products are not pesticides, rather a live bacteria that consumes organic matter that it comes into contact with. Regular application of this product keeps clean drains and sinks from accumulating enough organic matter to support a drain fly colony. However, simply pouring this product down the sink does not allow the bacteria sufficient time to do its job. Your Pest Management Professional has specialized equipment which converts the product to a foam allowing it to cling to the sides and crevices of the treated area.

By taking active steps to treat and prevent drain flies, many other insects will also find your commercial kitchen less hospitable… which is of course the whole point! Call Nextgen Pest Solutions today to schedule a pest control inspection of your commercial kitchen. Our experienced professionals can develop a custom protocol to address insects (including drain flies), rodents, mosquitoes, and anything else that may pester your customers or needlessly appear on your health inspection.