Low-level labyrinth, mortuary maze, Or a means to pick nits, from flea-ridden strays?

I wear black and white but I’m not alive. Cars must pause so people arrive. I look like a zebra frozen in place. What am I that helps you cross alive?

With brass, steel and nickel I help to unseal all manner of possibilities, I Bow then my blade bites, you turn me and then things open.

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.