Most people hire plumbers or drain experts to deal with their drain flies. However, we had a somewhat unique situation. Our drain flies were not in our drains. It took a lot of sleuthing for us to figure out they were in the soil under our basement. It turns out, we had leaky clay drain pipes that all ended up needing to be replaced, which meant digging up our concrete floors. Firstly, trenches were dug to replace the drains (three months ago), but the drain flies were still very much in abundance. We started counting how many we killed per day, and that number averaged at about 120. The leaking drains had made our soil wet and, combined with organic matter from tree roots that stretched under our house, we had the perfect breeding ground for drain flies.
Luckily, we had hired Muhammad in the past to deal with a different bug infestation (carpet beetles) so we knew we could trust him and his knowledge. When we called Muhammad, he came the same day. He listened patiently while we provided him with the full history of our experience and the results of our sleuthing. He was very willing to work with us as a team to solve our dilemna.
Since creating trenches in our concrete floor to replace the drains, our soil had eroded and subsided, which led to the rest of our concrete floors to shift and become unlevel. The remaining concrete had to be removed. Yes, a drain fly problem created this huge, very expensive and long lasting mess for us! However, the one benefit to removing all the concrete was it gave Muhammad access to all of the soil under our house to which he was able to apply treatments and insecticides on several occasions (he took a tiered/multi-treatment approach). I am so grateful we knew Muhammad. He was always responsive (always responded by the end of the day) and we actually joked that we had Muhammad on "speed dial" (for those that remember that feature). Because I am not confident any other company who advertises that they treat drain flies would have known what to do given our unique situation. If you Google "drain flies" the only information that comes up is how to treat them within drains - no one ever talks about eradicating them from soil.
Long story short, but with Muhammad's skilled and knowledge-based help (he also periodically consulted with other entomologists), we are now one month free of drain flies and are in the process of putting our basement back together. Thank you Muhammad.
