What Am I Riddles

Question: All things I devour: Birds, beasts, trees, flowers.
I gnaw iron, bite steel.
I grind hard stones to meal.

What am I?

Question: You can call me a home, but I have no doors.
Someone lives inside me, but leaves when there's no more.

What am I?

Question: A father goes to prison and the mother will have to sell her hotel, but their young daughter is happy.

How can these parents tolerate such ingratitude and what put them in this situation?

Question: Each morning I appear to lie at your feet. All day I will follow no matter how fast you run. Yet I nearly perish in the midday sun. What am I?

Question: I fly, yet I have no wings. I cry, yet I have no eyes. Darkness follows me; lower light I never see.

What am I?