K. pilae are roundish-oval mites. The males are up to 220 µm long and about 150 µm wide, females up to 356 µm long and about 300 µm wide. The four pairs of legs are short and stubby in shape and have five segments. At the ends of the extremities, males have unjointed grippers and suckers, while females have claws.
K. pilae lives off the substance of the beak, which it dissolves by means of a keratinase. They live primarily in the cere and at the base of the beak of the infected birds. They inhabit a single host throughout their life cycle; infection of new hosts occurs by contact.
The viviparous females drill tunnels in the epidermis where they give birth to six-legged larvae, which mutate through two eight-legged nymphal stages from the second of which the adults molt.