Edit in JSFiddle

var paper = Raphael(10,10,500,500);
//var myCircle = paper.circle(20,20,5);
var myArray= [];
for(var index=0; index<25; index++){
    var myCircle = paper.circle(index*20,20,5);
    myArray[index]= myCircle;
    }
setInterval(
    function(){
        for(var index=0; index<25; index++){
        myArray[index].translate(0,Math.random(10));
            }
    }
,5);

//if(myCircle.)