Newborns have a highly developed sense of smell. Though your baby can't yet recognize you by sight, he'll know you by your natural scent, and that's what he'll most want to smell. He'll also be drawn to the scent of your breast milk. These smells are connected to his basic need for comfort and food.

Do babies know bad smells?

It can't characterize stinky scents, which can pose a danger: Very young children usually don't realize that poisons or expired food smell “bad.” That will change when your critter turns 2. Then he'll recognize foul-smelling odors (like the contents of his poopy diaper).

Can smells harm newborn baby?

Try not to worry if you've just smelled the odd whiff of weed here or there during your pregnancy. This tiny amount of exposure is very unlikely to have harmed your baby.