Beneficial Nematodes (Steinernema feltiae, Sf) are microscopic, soil-dwelling organisms that help control fungus gnats, fly larvae, and other soil-dwelling pests naturally. They actively seek out pest larvae in the soil and eliminate them without harming people, pets, plants, or beneficial insects above ground. This add-on introduces learners to the hidden world of soil life and the important role microorganisms play in healthy ecosystems. Microscope needed for viewing.