My Ice Cube is Floating

This is actually nothing to do with ice cubes but that's the best analogy I could think of...lol

Anyway... I'm using this bit of code to make an object get smaller over time-

 function Update()
 {
     transform.localScale -= Vector3(0.001,0.001,0.001); // Reduce object size over time
 }

Which works great technically. However after a few moments the object is basically floating in mid-air. How can I get around this problem and keep my object on the ground?

Suggestions please guys ???