What's the name of this type of flies and how to kill them?

They're really small and I can't see their wings. Normally, I see them in public bathroom, especially in toilets.





What are they? Are their spray to kill them?

What's the name of this type of flies and how to kill them?
They're gnats.
Reply:Fungus Gnats.... And you must flush your sinks out, or use the Draino type products and hot water flush read the packageing of course... and if you have a plant near by... well it could be your green friends problem... and thats a whole other story.