The mites are blood feeders and attack resting birds at night. They are generally white or greyish in colour, becoming darker or redder when engorged with blood. After feeding, they hide in cracks and crevices away from daylight, where they mate and lay eggs. The mite progresses through 5 life stages: egg, larva, protonymph, deutonymph and adult. Under favourable conditions this life cycle can be completed within seven days, so populations can grow rapidly – causing anaemia in badly affected flocks of poultry. Young birds are most susceptible. The mites can also affect the health of the birds indirectly, as they may serve as vectors for diseases such as Salmonellosis, avian spirochaetosis and Erysipelothrix rhusiopathiae.