Insect and Spider Identification: Fruit fly identification, 5 by Dinu

Dinu wrote:
These are old pictures - from June 2010. But these fruit flies are common esp. in summer months every summer for as long as I can remember. They are very tiny. Picture is of the flies sitting on a small thread that was hanging from a reaper. The rest like that. They hover in front of our eyes and we have to drive them away often.

I have studied in school that these are Drosophilas. Looking for any help please.

Dinu