Answer:
It goes up and down the stairs without moving.
What sphinxes employ and players enjoy.
Sitting down you have it, Standing up you don't.
A young man wants to have it, but when he has it he no longer wants it. Blade in hand he attacks it And does his best to remove it. Yet he knows that it is all in vain.
When it's dirty this should never be aired in public.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?