getting beaten up by baby!

Jenna
My 4 month old has suddenly started punching me/grabbing and pinching my face and nose while I'm breastfeeding him. Today he put his hand in my mouth. It's funny and frustrating at the same time - but also keeps him awake while I'm trying to get him to wind down... anyone else's baby do this?! Wonder if there's a reason for it or if he's just exploring. Hopefully a passing phase!