Summary The iconic fly Thyreophora cynophila has long attracted the interest of entomologists but, despite its re-discovery in Spain and France, its biology is still poorly known. The larvae and puparium have been described in detail but their feeding habits on large carcasses remain largely unknown. Here, we took advantage of a carrion pile containing the remains of wild boar (Sus scrofa) and red deer (Cervus elaphus) as well as of two cow (Bos taurus) carcasses to search for T. cynophila larvae inside the bones and skulls. We document the occurrence of T. cynophila inside the cerebral cavity of dead animals, containing the brain. From the carrion pile, out of seven skulls, T. cynophila larvae could be found in five of them, and identified on the basis of their size, the shape and arrangement of the ventral tubercles, prothoracic spiracle and cephalopharyngeal skeleton. In contrast, no T. cynophila larvae could be found inside the nine bones we inspected. From the cow carcasses, no T. cynophila larvae could be found in the bones but one larva was found inside the cerebral cavity of one cow. In addition, other Diptera and Coleoptera larvae were found inside the bones.