They are obligatory ectoparasites of birds, and inhabit their feather quills where they feed on subcutaneous tissue and fluids.

[2] Quill mites have been recorded from hundreds of bird species, belonging to 95 families and 24 orders.

[1] A single fertilized female enters the soft calamus of a developing feather through the opening called superior umbilicus.

Due to this peculiar life cycle, quill mite populations are highly inbred and subjected to an extremely reduced (if any) sexual selection pressure.

[4] Additionally Spiroplasma bacteria are suspected symbionts, besides potentially the pathogens Anaplasma phagocytophilum, Brucella and Bartonella.