Individual task load in tunneling excavation of the Formosan subterranean termites

To understand individual participation in tunneling task, 27 workers (plus 3 soldiers) of Coptotermes formosanus Shiraki were marked and released in a 2-D arena provisioned with sand, and their time budgets in excavation were recorded by a camcorder. It was found that approximately 17% workers excavated at any given time, and only 2~3 workers tunneled continuously throughout the 4h observation. Approximately 18% workers never involved in the digging work. The foraging group size and age effect on this load division of C. formosanus will be discussed.