Bug Blog

How Little House Flies Differ From Domestic House Flies

Fannia canicularis, or the little house fly, is an insect pest that is well known for establishing infestations within and around homes. Little house fly adults are 3 to 5 mm in length, making them about ⅔ the size of domestic house fly adults. When little house flies are at rest, their wings fold in a manner that covers their backs, while domestic house flies hold their wings in a sort of V-shape. Much like domestic house flies, fruit flies, blow flies, stable flies, and many other fly pest species, little house flies congregate and breed on decaying organic matter, such as excrement and decaying fruits, vegetables and other rotten foods. While little house flies certainly acquire bacteria from their foul breeding sites, they are not considered as much of a disease threat to humans as domestic house flies. Little house flies are common indoor and outdoor nuisance pests, but they differ from domestic house flies in many respects that are worth noting for homeowners.

Little black fly females rarely enter homes, but males enter homes frequently, sometimes in great abundance. While domestic house flies tend to congregate in certain indoor areas where decaying organic matter provides the pests with an ideal breeding site, namely kitchens, little house flies tend to spread to every area within a home. When it comes to flight patterns, little house flies can be particularly annoying to a home’s occupants, as they tend to fly about aimlessly and erratically. Little house flies appear earlier in the year than domestic house flies, but due to the former’s intolerance for extremely hot conditions they may disappear during the summer season in Arizona. In some cases, little house flies may seek shelter within air conditioned homes once temperatures in Arizona begin to increase during the late spring and early summer. Little house flies are also less dependent on high moisture environments when compared to domestic house flies, which is why they commonly distribute to all areas within a home. Therefore, ridding a home of high moisture may not eliminate little house fly infestations. Little house flies tend to gather around door frames and porches, and they hover 5 feet above ground where they frequently collide with people’s faces.

Have you noticed that the body size of house fly pests tend to become larger as the spring progresses into summer?