Arixenia esau (Dermaptera) feeds on the skin of bats of the genus Cheiromeles. The food material is collected by the maxillae, lifted through the cibarium by the hypopharynx and then pushed into the oesophagus by the orally directed setae on the mandibles. Arixenia jacobsoni has less specialised mouthparts and feeds upon insects inhabiting bat guano in a similar way to many carnivorous labidurid earwigs. Hemimerus talpoides (Hemimerina), which feeds upon the skin of the giant rats of the genus Cricetotnys, cuts off food particles from the host with the mandibles and then passes the food material through the cibarium into the oesophagus by means of the maxillae.
The form of the head and neck of Arixenia can be derived from a pygidicranid or labidurid type and the apparently “primitive” features of the head of Arixenia can be explained as the result of a change of feeding habits from being carnivorous insects to external parasites of mammals. The head of Hemimerus so differs from those of the dermapteran types that this, together with consideration of other anatomical features, resulted in the Hemimerina having been regardod as a separate order of insects.