Peewee playes the shell game three shells and he has to guess where his treat is . Smell is a dogs sharpest sense. Next time a dog sniffs at you, think about this- just by smelling, a dog can tell where you have been and what you have been doing, what you have eaten, and even whether you are not feeling well. (Perhaps its a good thing that dogs cant talk.) The dog is using its nose the way you use your eyes to recognize people and figure out something about them. You know your little sister just came home from school because you see that she has her B backpack on; she had peanut butter and jelly for lunch because it is all over her shirt; and she looks might have a cold. A dogs nose enough to detect the scents your little sister picked up at school, the pb and j, and even the chemical changes that take place in her body if she is ill.