A new study shows when your baby's pacifier hits the ground, it may not be the best thing to wash it off before you give it back.
ABC News reports that researchers found if you hand it back to the baby without cleaning it , they'll have less allergies later in life.
They looked at 174 babies and their parents for several years and tested them for everything: allergies, asthma, and eczema.
They also asked the parents how they cleaned off the dropped pacifiers and found nearly half used their own mouths on occasion.
But by the time those babies were 18-months-old, they found they were less likely to have allergies because they were exposed to that bacteria earlier on in life.
But not everyone is convinced you shouldn't boil or rinse off the pacifier.
Critics say the long term effects aren't clear and that babies can become exposed to bacteria without their parents' help.