We have these little black bugs. we thought they were fleas, but they are not. they bite. what could they be?

Question

We have these little black bugs. we thought they were fleas, but they are not. they bite. what could they be?

Answer 1

I had no history of living bugs in my house.
It just happended one month ago.
I have tried every counter product available.
It is flying black -redish fruit fly -size insect.
It follows wherever we move in a house.
Its bite is nasty and very itchy.

Answer 2

It is very smll, like fruit-fly size.
It is very hard to catch, and not fragile.
It bites every night. very itch.