Answer:
What always comes into the house through the keyhole?
Old people and owls are said to be this.
An appropriately loud response to fear, excitement, or your team scoring.
A person's greatest asset.
You can do this with your friends. You can do this with your nose. But don't do it with your friend's nose!
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.