Never!
Anyway, that wasn't a riddle, it was an impossibility, here is a riddle:
What has a bed but doesn't sleep, has a mouth but doesn't eat, it can run but never walk, what is it?
[sub]I'mma go to bed, considering I have to get up early to get to the post box to send my brother his birthday present before the guy comes around and takes the post.
My brother's birthday is on the 28th, so it's best to send it now, to allow for bad postal service experiences[/sub]