Answer:
I have three feet but I cannot walk. What am I?
I am a million peopleβs wakeup call
You throw me out when you use me and take me in when you are done.
I am the state when a person is holding a person inside
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.
What is lighter than what it is made of?