Small yellowish/tan to black flies with red eyes flying around your house (specifically in your bathrooms and  kitchen - near fruit or compost).

What are Fruit Flies?

Fruit Flies or Peacock Flies belong to the family Tephritidae in the order Diptera.  There are about 300 species that occur naturally or have been introduced to Canada and the United States.  They range in size from 2 to 20mm and have marked wings with diagnostic patterns.  North American species are all associated with and breed in plants.   From an agricultural point of view they are the most significant family of flies.  This is due to a number of species being significant destructive pests of commercially grown fruit and vegetables.  A few species are also beneficial in that they attack noxious weeds. 

How did they get into my house?

There are numerous ways that Fruit Flies can get into your house.  Having said that, the most common source of infestations in Alberta is via infested fruit from your supermarket.  Once the flies are in your house the females lay eggs on any decaying fruit and vegetable scraps, in the drains in the kitchen and bathrooms and any other fermenting organic material.  Shortly after, the eggs hatch and maggots emerge.  Assuming appropriate conditions they pass through 4 instars and a short while later they pupate and adult flies emerge to begin the cycle again.  The entire cycle takes about 10 days.  In a very short period of time there can be literally dozens of them flying around your house.