There are several different kinds, but the one you pick doesn't do its job. What is it?

Answer: lock

More Difficult Riddles with answers

More Difficult Riddles

There are two bodies on the floor. They are surrounded by water and broken glass. How did they die?
There are two numbers whose product added to the sum of their squares is 109, and the difference of whose squares is 24. What are the two numbers?
There is a certain club which is for men only. There are 600 men who belong to this club and 5% of these men wear one earring. Of the other 95% membership, half wear two earrings and the other half wear none. How many earrings are being worn in this club?
There is a creature of God whose body is hard; it does not wish to eat unless you strike its head.
There is a man stood on top of a mountain frozen holding a peice of straw. How did he get there?
There is a puzzle which can be asked all day with a different correct answer each time. What is the puzzle?
There is a word in the English language in which the first two letters signify a male, the first three letters signify a female, the first four signify a great man, and the whole word, a great woman. What is the word?
There is someone, and there is always another, for without the other, there wouldn't be one
There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends. What is it?
They belong to me; they belong to you; They can make you feel happy or make you feel blue; They never end until the day you do.
They can float and tickle, but their sound is rarely heard unless you're a pillow or bird. What are they?
They have not flesh, nor feathers, nor scales, nor bone. Yet they have fingers and thumbs of their own. What are they?