J.J.
My son did it all the time when he was little. I wooried too, at first, but it soon came to be a great indicator of bed-time. Sometimes, when we would be cuddling, he would even play with MY ear!!! It was so sweet. And, to be honest, I miss it now that he has outgrown it. Enjoy it while it lasts. It's those moments of innocence that matter most!!!
Jen