Answer:
I'm the source of all emotion, but I'm caged in a white prison.
I sleep by day, I fly by night. I have no feathers to aid my flight.
The sharp slim blade, that cuts the wind. What is it?
In this place, people lie, people cry, and people ask why. In this place, people sleep, people weep, and people's solitude, they keep. What is it?
I'm tall in the morning and short in the noon. I disappear at night but I will be back soon.
What scientists might call your pooch.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?