Help Please!

[PatrickV]

i recently put all of my snakes on white paper towel to monitor for mites and today i noticed specks of blood in my BP's cage on the paper towel. He is male, about 7 years old. He was not the one who had mites in the first place and there is no sign of mites in his cage. I dont see any blood on his actual body and his face/nose seems normal. I dont understand what could be wrong, any help would be appreciated.