Most BLOX have an ability that is triggered by tapping. The exceptions are:
Rocky (The one that looks like a rock) – no abilities.
Dizzy (Rainbow BLOX) – ability is triggered after it has been grabbed.
Teardrop (Looks like a drop of water) – ability is to drop to the bottom of the screen if nothing is below it.
Tapping these BLOX will not result in the activation of their abilities. This adds to the challenge and strategy of the game!