I neglected to top some plant pots in my flat with gravel recently, and had a bit of a fungus gnat population explosion last month. I was worried it was getting out of hand again, but the entire generation seem to have all expired overnight at the same time (and I have since covered all exposed soil, so hopefully they have not managed to lay more eggs) which is great for my wellbeing but they also all expired in the same place, so I now have a fungus gnat mass grave on my living room floor o.O