Greed is a most terrible habit. Greed is when you look at something another person has and you wish that you also had it.
The problem with greed is that the greedy person remains worried all the time and also loses what he has. Here is a story about this.
There was a dog that once found a large bone that still had some meat on it. He felt very lucky to have found something like this without making any effort.
As he walked away with the bone, he passed by a pond and saw his reflection in it. The silly dog did not realise that it was himself in the water and thought that he was seeing another dog with a large bone in its mouth.
His greed made him think that he should first eat the bone the other dog has and then eat his own. So to make the other dog frightened, he started to bark at it.
However, as soon as he opened his mouth, his bone fell into the pond and he could not get it out again. Niether did he have his own bone nor any bone of another dog. Because of his greed, he was now left with nothing.
See children! We must always be grateful and content with what Allaah gives us and not wish for that which others have.