Minecraft wiki entry for Piston, associated text: When toggled between on and off rapidly with a gravity affected block (such as sand) above it, a piston can eventually break the block, which can be picked up as a resource. However, gravel broken this way never drops flint.
Mobs can spawn inside the piston head block.
Carpet can be placed on the piston extension block, and remains even if it is replaced with a solid block using /setblock.
In Bedrock Edition, the piston head is invisible and non-solid when placed with commands. The moving piston cannot be placed with block placement commands in this edition.
Piston head extend animations are different in Java Edition from those in Bedrock Edition.
The piston heads in Bedrock Edition look slightly different than the ones in all other versions.
The moving_piston is transparent and does not emit light.
If a light-emitting block is moved, the player can see it turn dark briefly. If an opaque block is moved, the player may see light passing through it.