Flying insects question

[newgardener2016]

So I did a small garden for my strawberry's and I have some very, very small flying black insects. Not sure what they are but I uploaded a couple pics of some, clearest I could get. What are they and how do I keep them at bay or do I need not to worry about them?
Thanks

 

[Chuck]

Looks like fruit flies. About the only way to control them is to kill their eggs which are in the soil. A spinosad drench works well.