By day, I lurk in backpacks, a quiet whisper of responsibility. By night, i am oft attacked and consumed by a nearby beast. By morning, i am frantically sought after, but i will never reach the backpack whole again. What am i?

Twelve pairs of guards in white stand proud in ordered rows. Each day they shield the lifeblood of their land, is one day of the century that they will stand. So well they’re trained: they breathe as one! Yet wield no weapon, nor ever see the sun.

Made of metal, I am a carpenter's best friend. Made of keratin, I protect the tip of your hand. As a verb, I am perfection, just as how you intend.

What bleeds another's blood when you kill it?

My first bit is the opposite of a pro. My second bit is where you rest your feet. Altogether, I comfort you when you are sad.