Answer:
Break it and it is better, immediately set and harder to break again
I am black when I am clean and white when I am dirty?
It doesn't live within a house, nor does it live without. Most will use it when they come in, and again when they go out.
Who lives in a house with one bedroom, 50 hallways, and ghosts lurking everywhere?
With pointed fangs it sits in wait. With piercing force it doles out fate, over bloodless victims proclaiming its might. Eternally joining in a single bite.
A red house is made out of red bricks. A blue house is made out of blue bricks. What is a green house made out of?