Riddle: When is the moon heaviest?
Answer: When it is full.
Riddle: How does a robot shave?
Answer: With a laser blade.
Riddle: I see without seeing. Noise is an ally. What am I?
Answer: A bat.
Short Riddles
Riddle: Where can happiness always be found?
Answer: In the dictionary.
Riddle: What can you break without hitting or dropping it?
Answer: A promise.
Short Riddles
Riddle: What came out from ONE hole and goes in to TWO holes?
Answer: Farts.
Riddle: What are the next two letters in the series? D E J A F E M A A P M A J U J U _ _
Answer: A U First two letters of months of the year.
Short Riddles
Riddle: Where do pilots keep their personal things?
Answer: In air pockets.
Riddle: Why is a pencil like a riddle?
Answer: It's no good without a point.
Riddle: When is it right for you to lie?
Answer: When you are in bed.
Riddle: What is more amazing than a talking dog?
Answer: A spelling bee.
Riddle: Who does the ocean date?
Answer: It goes out with the tide.
Riddle: What does no man want, yet no man wants to lose?
Answer: His job.
Riddle: Why is your nose not 12 inches long?
Answer: Because it would then be a foot.
Riddle: What table has not a leg to stand on?
Answer: The multiplication table or periodic table of elements.
Riddle: How do you know when your alarm clock is hungry?
Answer: When it goes back four (for) seconds. 
Riddle: What is the most slippery country in the world?
Answer: Greece!
Riddle: The more you dry yourself with me the more I get wet. What am I?
Answer: A towel.
Riddle: How far can a dog run into the woods?
Answer: Halfway, any farther and he would be running out of the woods.
Riddle: I know a word of letters three, add two and fewer there will be?
Answer: The word "few". Add "er" and it becomes fewer.