Now you know why they make all those sweet little cloth bibs. But there may be some things you don't realize about your little one's seemingly favorite activity: you have to live with it  -- at least for now. "Some babies just don't know what to do with their spit, so out it rolls," says Andrea McCoy, M.D., a medical director at Temple University Children's Medical Center in Philadelphia. If the skin around your baby's mouth gets irritated, "slather it with a moisturizer such as Vaseline, Aquaphor, or Eucerin," she suggests.

Babies who have reflux may be more prone to drooling because swallowing their saliva aggravates the chronic acid burning in their throat. teething is an unlikely cause of a leaky mouth (though it can make one worse). Drooling typically begins between 2 and 4 months, but in most cases, those first pearly whites don't pop through until 6 to 9 months. So don't break out the teething ring if dribble is your baby's only symptom.