This has been occurring for a few months now and neither I nor the local vet can place exactly what is happening. We think it is mites, or some other form of parasite, but my female mouse is completely fine (as far as I have observed).
I have tried Ivomecten several times as well as scattering diatomaceous earth around the cage and desk that he is on. These haven't worked, so we are currently looking for something else. This seemed like an obvious case of mites, but my female hasn't been affected (no scabs, balding, or itching). What could this be?