code: function ( dt )
      {
          // every 1/2 seconds display moles randomly
          this.timer += dt;
          if ((this.timer) >= 500) {
  
              for (var i = 0; i < 9; i += 3) {
                  var hole = me.Math.random(0, 3) + i;
                  if (!this.moles[hole].isOut && !this.moles[hole].isVisible) {
                      this.moles[hole].display();
                  }
  
              }
              this.timer = 0;
          }
           return false;
      }
docs: /*
  update function