A study of the diurnal rhythms in the postfeeding dispersal of the larvae of two coexisting carrion blowfly species, Calliphora vomitoria and Lucilia caesar, from corpses was conducted in the field. Larvae of both species dispersed exclusively at night. The emigration of white coloured larvae is risky. By dispersing at night the larvae minimise interactions with diurnal and crepuscular predators.