I've had these tiny flies in my house for about 2 weeks.
No fly spray kills them.
They move so quickly and are hard to keep track of in flight.
I have to cover every item of food. I even found three in the fridge.
And I am not alone. Apparently these flies lie in wait and then enter the fridge door as soon as it's opened, but you barely notice.
I have to be on my guard when eating. One landed on my hand as I was lifting my fork to my mouth.
So prepare and beware.