Answer:
People see through me, but none pass through without killing me. I can be anywhere, and can be seen double or single. What am I?
I have a hundred legs but cannot stand. I have a long neck but no head. I cannot see and I help keep your house neat and tidy.
I go up, let out a load and then go back down. What am I?
My full powers come when my makers are dead. I await a heavy hat to put on my head. What am I?
By myself, I'm practically nothing. Worthless as a leader, but when I follow a group, their strength increases tenfold. What am I?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?