Answer:
I'm simple for a few people, but hard for them to hear. I live inside of secrets and bring people's worst fears. What am I?
Without me everyone would lose their head.
I shift around though always slowly. I never move more than a few inches at a time. A large movement by me can kill many people. I am huge yet unseen by humans.
I have a hundred legs but cannot stand a long neck but no head and I eat the maid's life. What am I?
I have a head but never weeps. I have a bed but never sleeps. I can run but never walks. I have a bank but no money. What am I?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.