Answer:
The more you look at it, The less you see.
What always comes into the house through the keyhole?
A mechanism to discover who is following you.
What time starts and stops with an ānā?
MT_TF_S What are the missing letters? Why?
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.