Without closer inspection, these appear to be Fungus gnats.  Fungus gnats are small, dark, short-lived gnats. The larvae feed on plant roots and fungi, helping in the decomposition of organic matter. The adults are 2–5 mm long and are important pollinators of plants and carriers of mushroom spores. They carry diseases such as pythium on their feet. They may be quite annoying to humans as they fly into their faces, eyes, and noses.

If you have plants in your home, this is where they could be coming from. In houseplants, the presence of fungus gnats may indicate overwatering; they may be feeding on roots that have sat in drain water too long and are thus rotting, or the gnats may be attracted to fungus growing in saturated topsoil. Consequently, allowing the soil to dry may reduce their numbers. They are sometimes also managed by placing a layer of sand or indoor mulch on top of the soil around plants.

These little guys can be very annoying. They tend to hide in the first inch of moist soil that contains a lot of organic material. They could have come in from outside on plants that you are overwintering, or often they come directly from a nursery or garden center.  If the infestation is new, let the soil of infected plants dry out completely, which will kill the larvae.  If, however, the infestation has been going on for a while, you will have to take more drastic measures.

One option is to remove the top 2 inches of potting mix from the infested plants and discard immediately. Then replace it with sand, which is free of organic matter and dries out quickly.  Removing the top 2 inches will have removed the larvae already laid. Let the soil below dry out completely before watering.  This should eliminate all fungus gnat larvae present and prevent new eggs from being laid.

Now you need to get rid of the gnats that are still flying around.  Gnats are very attracted to sweet liquid like grape juice or cheap alcohol-free wine.  Pour the liquid into a small saucer, and place it near the previously infested plants. Let it sit overnight. You will find a collection of dead fungus gnats floating in the liquid.  Discard and refill until the adults are all gone. Another option would be using the yellow sticky cards to capture the flying gnats.

Other sites to visit:

http://www.getridoffliesguide.com/how-to-get-rid-of-gnats-inside-house-kitchen-outside/

http://extension.colostate.edu/topic-areas/insects/fungus-gnats-as-houseplant-and-indoor-pests-5-584/

I hope this was helpful. Feel free to contact us again if you have further questions.