Don't forget to clean your home's roof gutters and downspouts regularly as drain flies are attracted to standing water, which can accumulate in clogged gutters. Also, ensure all windows and doors have proper screens, and check for any cracks or gaps around pipes, faucets, and toilets, as these can provide entry points for the pests.
To eliminate the source of the problem, inspect your plumbing system and look for any signs of mineral buildup or corrosion in the pipes. Consider installing a drain screen or filter to catch hair and other debris before they go down the drain.
For an eco-friendly approach, try using a mixture of equal parts baking soda and white vinegar to create a natural trap that will break down food particles and eliminate odors. Pour the solution down the drain and let it sit for a few hours before rinsing with hot water.
In severe cases, consider hiring a professional plumber to inspect and clean your pipes, as they can identify and address any underlying issues that may be contributing to the infestation.