Little is known about their biology, though Zikan reported the larvae of
Gauromydas heros live in the subterranean detritus "pans" of
Atta ants in southern Brazil, where they appear to be feeding on detritivorous
Dynastinae (
Coelosis spp.) larvae. In the U.S.,
Mydas brunneus, Mydas clavatus, and
Mydas tibialis larvae are predatory on deadwood-feeding scarab beetle larvae (
Osmoderma spp.) and can be found in standing and downed trees with extensive heart rot. Others (e.g.
Mydas maculiventris) are subterranean and feed on "white grubs" (Scarabaeidae: genus
Phyllophaga) that attack the roots of grasses and could be potential biocontrol agents of white grubs in sod production areas. Larvae typically take two or three years to mature. Adults of several species are avid flower visitors and act as pollinating agents. Rattlesnake master (
Eryngium yuccifolium) is a favorite nectar source in the Midwest. They are infrequently encountered as the adult lifespan can be quite short. ==Description==