It’s always puzzling how fast insects can find their way to houseplants, once the windows close. Fungus gnats just seem to appear out of nowhere and begin destroying our otherwise happy, healthy plants and seedlings. They’re those tiny black flying insects that disperse in a cloud when you touch your plant. They may have hitched a free ride in on our potting soil, but we don’t have to make them feel welcome. There are some safe and effective means of controlling this annoying garden pest.