An aqueous extract of German cockroach, Blattella germanica (L.), fecal material was evaluated for inducing trail-following behavior in German cockroaches. In arena tests the fecal extract was found to stimulate trail following in 74% of adult male cockroaches. Significantly fewer cockroaches (22%) followed water-treated (control) trails. Residual activity of the fecal extract trails was evaluated by bioassay after the trails had been stored in the refrigerator or in the open air. Although trails stored in the refrigerator showed no decline in activity after 14 d, those stored in the open air declined significantly after 3 d, inducing only 40% of adult male cockroaches to follow the trail. After 7 d the activity of trails stored in the open air was further reduced to 23%. The ability of fecal-extract trails to influence trap catch in monitoring stations was determined by bioassay. Paper trails treated with fecal extract or water were positioned between cockroach harborages and monitoring stations inside 122-cm² arenas. The presence of the fecal extract-treated trails significantly enhanced trap catch. Mean catch in the traps with fecal extract trails was 28 cockroaches compared with a mean of 11 cockroaches in the control traps. The trap catch ratios of adults to nymphs in the treated and control treatments were not significantly different.