Riddlebox 1

She smiles reassuringly, "You are correct!!!! When a child is born (the beginning of life---morning) he walks on all fours, but when he is a man (The middle of his life---day) he walks on two legs, and finally as he gets old (the end of his life---night) he can no longer walk on his own and requires the assistance of a cain making three legs total. I see you are who you say you are and now I must tell you where to find your next riddle. An old hunter lives on the outskirts of Yellowstone National Park, he lives in the only beige colored house around that area. His name is Marcus Polus and tell him you were sent by me." After thanking her repeatedly for her time, you set out to find Marcus Polus. As you approach his door an old man jumps out waving a shotgun asking what you are doing on his property. After you calmly tell him you were sent by Golda, he introduces himself and invites you in. After endless chatter he explains to you that you must answer one riddle before he can give you the next location to go to, but there's a catch....If you get this one wrong he explains he'll be forced to use his shotgun since the wrong person knows of "the secret". He begins as follows; "I run but never walk, I have a mouth but never talk, what am I?" You carefully consider possibilities and the closest answer you can think of is******************* YOUR LIFE IS ON THE LINE!!!!! Better get it right!