Kids who suck their thumbs for years can force their teeth out of alignment. But they’d probably need braces anyway. The good news is: It reduces their risk of developing allergies! That’s from a study of over a‑thousand kids in Pediatrics. Because kids’ fingers are disgustingly germy. And by regularly ingesting those germs in small amounts, kids build up a tolerance to pollen, pet dander, and dust. And kids who suck their thumb AND bite their nails get an even bigger immune-boosting effect!