Why does Handheld.Vibrate (); not vibrate my device ?

I need my Android device to vibrate after an object collides with another object. I’m trying to use Handheld.Vibrate (); but no vibrations happen when the collision happens. Here is the code:

if (radiusCheck.gameObject.tag == "Crowd") 
			{
			Handheld.Vibrate ();
            }

Either:

  • your device doesn’t support vibration
  • radiusCheck.gameObject.tag != “Crowd”