Answer:
What five-letter word becomes shorter when you add two more letters?
A house with two occupants, sometimes one, rarely three. Break the walls, eat the boarders, then throw away me.
They belong to me; they belong to you; They can make you feel happy or make you feel blue; They never end until the day you do.
My life is often a volume of grief, your help is needed to turn a new leaf. Stiff is my spine and my body is pale. But I'm always ready to tell a tale.
There are millions of me. I am very small but when moving fast I am deadly.
You use it between your head and your toes, the more it works the thinner it grows.