To better understand the intrinsic control of caste in Formosan subterranean termites we evaluated if group density can affect worker JH titers and soldier numbers. Worker groups without soldiers of 50, 100, 500 and 1000 individuals were placed in Petri dishes and JH titers were examined at 10 day posttreatment. Termite groups with 10% soldiers were similarly evaluated. As density increased JH titers significantly increased whether soldiers were present or not. JH titer increases were accelerated when soldiers were absent.