Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Pheromones enable communication, which is vital for organisms like ants that live in a large community.
Pheromones enable what, which is vital for organisms like ants that live in a large community?

Cells are the  basic building blocks of the human body.
What are the  basic building blocks of the human body?

Gravity causes rocks to roll downhill.

Which force causes rocks to roll downhill?