Answer:
Soft hairy from door to door. I am the pet that always stays on the floor.
Deep, deep, do they go. Spreading out as they go. Never needing any air. They are sometimes as fine as hair.
Iām hard as a rock and as light as a feather. Iām passed on to one another. Poor people need me and rich people have me.
What gets whiter the dirtier it gets?
I am like thunder in your cranium
A little house full of meat, no door to go in and eat.