For example, accumulation of poultry droppings is an excellent filth-fly breeding medium. Latest figures by Statistics Canada show that an average of 21,814,000 laying hens were raised throughout Canada in 1994, resulting in over 2 billion pounds of manure for filth-fly development. In addition to egg production, another 720,785,000 chickens were raised for meat in 1994. This number of birds produces a lot of 'breeding medium'. They cluster on the backs or underside of cattle, spending most of their lives on the animal and feeding up to 20 times a day.
Stable flies are blood feeders.
Their painful bites cause severe irritation and 'shaking off' motions. Though this disturbs the flies feeding they will return repeatedly to bite and feed again in order to obtain a full blood meal. As a result milk production as well as weight gain and feed conversion efficiency in dairy and feedlot cattle is reduced. House flies do not cause direct economic loss through reductions in animal performance, but are a serious pest because of their ability to produce large populations which enter human domiciles. Because of their association with filth, ability to contaminate food, and severe annoyance to humans, chemical control methods are commonly applied to reduce fly populations and avoid legal actions from homeowners or municipalities in surrounding urban areas.