Answer:
Deep, deep, do they go. Spreading out as they go. Never needing any air. They are sometimes as fine as hair.
I have six faces but not even one body connected 21 eyes in total but cannot see.
What has many teeth but can't bite?
I am lighter than air but a hundred people cannot lift me. Careful! I am fragile!
I am your most powerful weapon; I come before your eyes. I help you seek the truth, yet I often give you lies. What am I?
A little house full of meat, no door to go in and eat.