Hi, I was petting my bunny earlier today and found a small black bump on his head. He likes being scratched on the his head and I could feel the bump as I scratched. After investigating I found it and thinking it was just something stuck in his fur I tried to pluck it out. But after some futile attempts my bunny jerked his head back as if in pain. I wasn't trying too hard so it surprised me that it hurt him. I'm guessing that this bump might be a mole or something stuck to his skin which is why it hurt him. Any ideas to what it is?