Hi, Fungus gnats are a problem sometimes. One thing I do is to avoid using peat moss unless the seeds really want it (e.g., azalea seeds). Peat moss and too-damp soil can lead to amazing numbers of fungus gnats. I have found that insect bombs and foggers (that are marketed to clear up fleas inside a home) take care of fungus gnat infestations, and I have not observed any damage to seedlings (I suppose damage could happen). A sure approach involves misting plants and soil surfaces to wetness with pyrethrin or other low-toxicity (for humans) insecticide; this will kill the larvae/eggs in the soil. You just need to be sure that the insecticide is safe for your seedlings. If you don't treat the entire collection of seed pots and nearby houseplants the fungus gnats can recolonize quickly. One email friend recommended using fly strips (sticky paper), I have not tried this approach. The goal is to trap all emerging adults before they can lay eggs in the soil. LINK: OSU Fungus Gnat Factsheet http://ohioline.osu.edu/hyg-fact/2000/2114.html Cordially,