Before I tell this story I want to make the point that I keep a VERY clean fish room. All my fish foods are kept in tight containers, and most of it is kept in a fridge or freezer to preserve its freshness. I take out the garbage at least three times each week, especially if there is something stinky in the trash can. The rare dead fish are not tossed into the garbage, they are flushed. I sweep the floor once a week. I flush out the drain gutters once a week by putting a hose into each of the open ends, just in case something that can rot gets into the gutters. I take the cleanliness of the fish room very seriously!
So I was very surprised, and somewhat concerned, this week when dozens of green bottle flies showed up in the fish room. You have probably seen these flies before. They are a medium size fly with an iridescent emerald green color. Pretty for a fly, but not something that I want infesting the fish room. The green bottle fly is a carrion fly, which means that it lays its eggs in rotting organic matter. My immediate reaction was to find the dead carcass where the flies were breeding. I ransacked the fish room. Nothing. Nothing stinks like dead flesh either. I have no idea where the flies are coming from, but I have to assume that they are getting into the basement from within a wall where there is something dead. I am confident that my room itself is not producing the flies. So what to do with the flies?
When life gives you lemons, make lemonade. I have been given flies, so I will use them for fish food. They are pretty easy to catch with a dry fish net. Just leave one light on in the fish room and all the flies go to that place. So far there have been a out a dozen flies at a time in the fish room, so I spend a few minutes catching all I can for a few minutes and feeding them to the fish. The life cycle of the fly is long enough that if I catch them a couple times every day I should be preventing them from laying more eggs. Eventually the flies will disappear. Until that thankful day the fish will get some great live food!