Young and adult chicken mites crawl from their hiding places at night to feed on the birds. Fowls become unhealthy and hens stop laying. Presence of the northern fowl mite is indicated by greasy patches of feathers on well-defined areas of infested fowls.
High infestations can cause reduced egg production, general unthriftiness and possible death.
History Eggs of the chicken mite are laid in cracks in the walls and in floor litter. Greyish mites feed upon the fowl's blood and then leave the birds. After feeding on blood they turn reddish. There are many generations per year, and the mites may live in a poultry house when no hens are present for 4 or 5 months even in winter. Northern fowl mites live permanently on the birds, and may also have several generations per year.