RIDDLE

Al got the answer that I had in my book but I also liked the one Di gave. She said nose. I have to go with what is in my book. I think I used that riddle before but everybody knows I had a birthday Sunday and may be getting a little forgetful.
ANSWER:What can run but can't walk?

WATER

TODAY'S RIDDLE:

What is black when you buy it, red as you use it, and grey when you throw it out?