Daily movement of marked termites (C. formosanus) following their release into an extended foraging arena was examined to develop a population estimate model with a single mark-recapture protocol. The model was designed to solve the heterogeneity problem of recapture probability due to the non equilibrium state of marked termites. The diffusion pattern of marked termites in the arena exhibited four phases, exponential decay phase, linear decline phase, equilibrium phase and post-equilibrium phase. The equilibrated proportion of marked termites was estimated by a linear regression using equilibrium phase data with the regression slope approximates zero. Population estimates with the equilibrated marked proportion were compared with the known population in the arena.