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Reporting
Houseplants ...... were the turning point? If YB's fruit fly juice doesn't take effect (which it will, I use it too) then you probably have fungus gnats. The potting soil may have enough spaghum moss in the mix to make a great habitat for them and they feed on small roots (can eventually kill young plants). I've tried chemical soil treatments and they were only just okay as I didn't want to harm the plants. It might work for you. What I really liked were something called "Bug Stix". It is a sticky sheet on a stick that you put in the pot, it's the size of a bookmark, 1.5" x 6". Very shortly, no more fungus gnats laying eggs in the soil with the larvae consuming the roots ... more than just pesky flying things!