as you see they all playing just like each other
how can I make them to play randomly?
I mean one of them plays at sprite 9, other plays at sprite 2, …
how can do this very very very simple?
In the script attached to this object, you can write in the Start() function :
myAnimator.Play(“Default”,0,Random.value);
nothing :), I just wonder is that possible or not, I just don’t want to make other object ,I want them to play randomly 
and I don’t really know how to do that.
make a array and put all the animations on it and generate the Random number as between your array.length() and call the index number animation to play on it
Your question is a little confusing. I think you don’t want to start amination from starting all the time. Sometimes you want it to start from the middle or from some other point. Right?