Bloody Mess

We all know baby's nails grow really fast and I file my LO nails every morning, but often than not, it feels sharp later in the day. Lately he's got a habit of pulling his left ear a lot especially when he's sleepy or hot. He'll often get scratches either behind his ears or on his face sometimes, but he has outgrown mittens. Last night he scratched so hard on his ear, there was quite a fair bit of bleeding, and poor bubz crIed murder. Can't see that much from the photo as I've wiped it off and stopped the bleeding ofcoz before I thought of taking a pic. What I end up doing was to put socks (lol) on his hands to avoid further damage. Anyone knows why he pulls his ears? My friend suggested teething?