Riddle: This thing runs but cannot walk, sometimes sings but never talks. Lacks arms, has hands; lacks a head but has a face. What is it?
In the riddle it is said that this thing runs but cannot walk, this is because of the phrase run out the clock or run down the clock. However, a clock, obviously, cannot walk because it is just an object.
Also, a clock has three hands which indicate seconds, minutes, and the hour but does not have arms, again, since it is only an object. In addition to these, a clock has a face which is also known as a face dial or briefly a dial but does not have a because of not being a living thing.
The answer of this riddle is a clock.