Answer:
It is weightless, you can see it. If you put it in a barrel it will make it lighter?
Two horses, swiftest traveling, harnessed in a pair, and grazing ever in places. Distant from them.
I'm tall in the morning and short in the noon. I disappear at night but I will be back soon.
Runs smoother than any rhyme, loves to fall but cannot climb!
Lighter than what I am made of, More of me is hidden Than is seen.
People take me on walks and I run and have fun. What am I?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?