What always comes into a house through the keyhole?

How can a man go eight days without sleep?

Move three sticks of the spiral below to form a square.

In the four images below, can you find the odd one out?

What has 13 hearts but no other organs?

One evening there was a murder in the home of a married couple, their son and daughter. One of these four people murdered one of the others. One of the members of the family witnessed the crime.

The other one helped the murderer.

These are the things we know for sure:

1. The witness and the one who helped the murderer were not of the same sex.

2. The oldest person and the witness were not of the same sex.

3. The youngest person and the victim were not of the same sex.

4. The one who helped the murderer was older than the victim.

5. The father was the oldest member of the family.

6. The murderer was not the youngest member of the family.

Who was the murderer?

Which English verb becomes past tense just by rearranging the letters?

I have an eye but still cannot see.

Who am I?

The first person saw the bridge step on it and crossed,
the second person saw the bridge did not step on it but crossed,
the third person did not see the bridge did not step on it but crossed.
Who are these people?

A man was driving a black truck. His lights were not on. The moon was not out. A lady was crossing the street. How did the man see her?