Answer:
Put into a pit, locked beneath a grate, guarded through the night, yet it still goes out.
What travels from house to house and is sometimes narrow and sometimes wide but always stays outside?
What is it that has four legs, one head, and a foot?
What is it that makes tears without sorrow and takes its journey to heaven?
Once they sailed the sea, now they surf the web
You use it between your head and your toes, the more it works the thinner it grows.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?