 The main difference is that the female pregenital apodeme and epimerites IV are separated, while in the latter they are connected and form a distinct structure.Feather mites (subclass Acarina, family Proctophyllodinae) are ectoparasites that live in between the barbs of feathers and are found on nearly every bird species currently described.It was previously believed that these mites had a parasitic relationship with their hosts but it is now thought that most species are more commensal with their hosts.