I recently adopted a cat that is almost 8 mo. old. He is very sweet and affectionate usually. At night he will lay on the pillow behind my head. He will be purring, or be asleep. Then he wakes up and starts clawing my hair and grabs my face, sometimes draws blood. His ears aren't back, it seems like he is playing, but it hurts! Anyone know why he could be doing this and how to stop it?