They don't always come up by themselves, some don't come up at all. Usually you start trying to get them up in the first few months. Some people wait until after teething, but still work on it right away.
If they don't come up at a young age, then you have to help them along by shaving and taping them. Try doing that, but you might want to find out when the "cut-off point" is for their ears coming up so that you aren't working in vain.
__________________ Anna  and  Wobie |