Dirty dishes that sit around too long can grow germs. These germs can make you sick. You can help out in your house by getting those dishes to the sink where they can be washed.
Some kids help out by doing the dishes at their house.
It's safer to just let them dry in the dish drainer and put them away later. When you are making a snack or something to eat, always use a clean knife, spoon, or fork. Dirty utensils can have germs that will make you sick.