It cannot be seen, it cannot be felt,
Cannot be heard, cannot be smelt,
Lies behind stars and under hills,
and empty holes it fills.
Comes first follows after,
Ends life kills laughter.
Answer: Darkness.
This riddle appears in the following downloadable PDF files:
Can you solve one of the most famous logic puzzle ever?
Memory Matching game for kids, adults and seniors.
Connect the matching tiles and pop them all.