Many have heard it, but nobody has ever seen it. It will not speak until spoken to. What is it?

Answer: Echo

More Difficult Riddles with answers

More Difficult Riddles

Many hear me, but no one sees me, and I only speak when spoken to
Many-manned scud-thumper, Maker of worn wood, Shrub-ruster, Sky-mocker, Rave! Portly pusher, Wind-slave. What am I?
Marco and Bob have been the best friends ever since they were little kids. They are also very competitive. Throughout the years they have challenged each other to do both physical and mental challenges. And they completed the challenge. But one day Marco thought of something to challenge Bob to do - something he could start but never finish. The average man could do it and so could Mark and they were both the same sex and the same size. It is a physical challenge. Can you figure out what it was?
Marking mortal privation, when firmly in place. An enduring summation, inscribed in my face. What am I?
Mobsters judge the quality of a vehicle by the size of this
More precious than gold, but cannot be bought, Can never be sold, only earned if it’s sought, If it is broken it can still be mended, At birth it can’t start nor by death is it ended.
My coat keeps me safe From damage that’s near. I cause you happiness, sadness, Anticipation and fear. On the outside, I am put under judgment of price. But my insides have far more value That not even MONEY can suffice.
My first half is normally made of stone, my second is crazy, and I taste sweet when complete.
My first is a body of water. My second is me. My third came before. My fourth before all three. My fifth sounds like my first. My sixth is in a lake. Put all six together to make an animal that will keep you awake.
My first is a creature whose breeding is unclear. My second, a price you must pay. My whole can be found in the river of Time and refers to events of today.
My first is a creature whose breeding is unclear. My second, a price you must pay. My whole can be found in the river of Time and refers to events of today. What am I?
My first is an insect; my second is a border; my whole puts the face in a tuneful disorder.