The dampwood termite Zootermopsis angusticollis lines nest chambers and galleries with fecal pellets. The antifungal properties of feces were tested by recording germination rates of spores of the fungus Metarhizium anisopliae that had been incubated with various concentrations of fecal material. The presence of fecal pellet material significantly decreased the germination rates of spores relative to those of control spore solutions lacking fecal material. Spore germination rates were inversely proportional to the amount of fecal matter present in the spore–feces suspensions but were independent of incubation time. The fungistatic effect of the fecal material is virtually immediate and does not require prolonged contact with spores to inhibit germination. This mechanism of biochemical protection may reduce risks of fungal infection in termite nests.