The efficacy of a dry, ready-to-use (RTU) termiticide formulation of fipronil was evaluated against termite foraging activity and survival by injection into foraging tunnels of Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) in a laboratory study. Groups of workers (older than 3^rd instars) were placed in bioassay units consisting of a group site and a feeding site connected by termite tunnel(s) within a soil-filled Tygon tube. Two treatments (0.15 and 0.30 mg a.i. fipronil per treatment) were conducted by injecting the doses into a foraging tunnel near the feeding site. Bioassay units were monitored for termite movement utilizing Termatrac® T3i until no movement was detected. Termite movement ceased at day 5 and 7 for the 0.30 and 0.15 mg dose treatments, respectively. Dissection of the bioassay units confirmed 100% mortality at the days when both visual observations and Termatrac T3i indicated no termite movement. Termites in the treated units constructed significantly fewer tunnels post-treatment compared to control termites. Our results provided strong evidence for the efficacy of the dry RTU fipronil formulation against R. flavipes activity at the group level when a single tunnel was treated.