# What to call an Object that falls only when it's collided with?

I am currently working on Objects/Blocks for my 2D Jump'n'Run. Now I want to add a new type of block, which falls down only if the player/an actor collides with it. But I don't know what to call this type.

Or more generally: Objects that only do stuff/change behaviour if interacted with.

• How should I name the first type and
• the second more general type?

• Some physics engines have a disabled property for disabling the body and not consider it when performing a simulation step. Some have an auto_disable flag that allows the body to disable itself when it's not moving for a period of time; these bodies are re-enabled upon a collision with another object.