Why do guys always leave their laundry in front of the hamper instead of putting it in the hamper?

There are four men in my house, two sons (20 & 21) husband and father in law, 4 yr old granddaughter and myself. My granddaughter puts her clothes in, i put my clothes in, but........no one else.....unless of course I have them dumped on the floor and separated ready to be washed. Then of course they put them in then. What is up with that? Is it a mind game? Are they doing it purpose? Does this happen to anyone else?