When babies teethe, their first teeth begin pushing through their gums. This usually starts around six months old and continues until they have a full set of baby teeth, around age three. The process can be uncomfortable or even painful, which is why teething babies often drool more than usual, chew on everything they can grab, and sometimes become fussy or cry more often.

You can see evidence of teething when a baby gnaws on a teething ring (a specially designed toy that's safe to chew on) or when parents gently rub their baby's sore gums to provide relief.

People sometimes use the phrase teething problems or teething troubles to describe the early difficulties with any new project or system. When your school introduces a new lunch line procedure and it's chaotic at first, those are teething problems: temporary struggles that happen while everyone adjusts to something new. Just as babies eventually get through the teething stage and end up with a mouthful of teeth, organizations work through their teething problems and eventually run more smoothly.