What causes small black flies in the house?

Answer by  Alisha20 (30)

Small black flies, often known as fruit flies, are typically caused by anything in the house that is spoiling or fermenting, especially fruits and vegetables(hence their name) as well as other wet things like mops and rags.

Answer by  cdonz (80)

The cause of the small black flies are most likely food. The flies love anything they can eat. Also, if one of the doors or windows is open they are likely to fly in. Be careful, because once one group of flies gets in, all of the others are going to fly in too.

Answer by  AnnaTeague (806)

Food attracts them, especially fruit attracts the tiny black flies. Additionally, dirty pet litter will attract black flies. Keeping these items clean and making sure your screen doors are in good working order will help. The Pest Strip or flypaper will catch most of the ones which remain. Pesticides are smelly and ineffective against these pernicious pests.

Answer by  Ferret (118)

Those are most likely gnats. They are attracted by garbage and other dirty areas in the house. Just make sure to keep your house clean, and they will disappear.