Answer:
A time when they're green. A time when they're brown. But both of these times, cause me to frown. But just in between, for a very short while. They're perfect and yellow. And cause me to smile.
People are hired to get rid of me. I'm often hiding under your bed. In time I'll always return you see. Bite me and you're surely dead.
What goes through the door without pinching itself? What sits on the stove without burning itself? What sits on the table and is not ashamed?
What is it that has four legs, one head, and a foot?
When I'm born I fly. When I'm alive I lay. When I'm dead I run.
I flow from the Homer’s mouth when he sees doughnuts.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?