Some Hawaiian cavernicoles appear to occupy areas of Kazumera Cave for less than two days at a time. It is thought that they appear from and disappear back into the system of cooling cracks, channels and vesicles present in the surrounding lava flows. This ‘mesocavernous habitat’ is thought to be extensive, to contain tree roots and detritus on which cavernicoles feed and to provide them with a humid microclimate which is subject to fewer perturbations than the larger and draughtier caves. For these reasons it is suggested that the ‘mesocavernous habitat’ is the principal habitat of Hawaiian cavernicoles, though some inhabit caves where they offer a suitable microclimate, or else make periodic sorties into caves in order to exploit cave-based resources.