gorsneg

hello! i just noticed that my budgie Frunze have some sort of half-healed "wound" or "messy spot" with dirty blood-looking covered feathers around...looking like a navel cord wound in humans...his is usual, good appetite, no diarrhea, vomiting...and I just have seen him scratching his stomach with beak and legs! He seems little bit sleepy ( but may be it's just what i imagine- he walked a lot today out of the cage) so far doesn't show any signs of sickness...Please, help me...What can it be? I am very worring!!