^^ Not on his head but in his diet.No, try fresh frozen vegetables after being thawed out and more seeds or more pellets - whichever is not there now.
It could be a number of things but the first thing I thought of was this bird trying to get out of a cage ( possibly when you aren't around) and rubbing that particular spot on the bars. Be diligent looking for any collective feathers from this area of his head on the cage floor or area surrounding it's cage. If you are gone part of the day and can set up a video camera that will run while you're gone to see what it does when it's by itself might tell you more about those missing feathers. You might also want to move the budgies further away ... like across the room to see if that has any change as well. You might also crush some pellets into a fine powder and sprinkle some on top of veggies to get him to try eating the pellet dust off of the vegetables. You've always got to think outside of the box and come up with different tricks to get them to try something.@Mockinbirdiva thanks for replying I have two other budgies in a cage nest to his but they don’t have any feather problems. My Ringnecks diet mainly consists of pellets but I slowly introduce vegetables and fruits but he never eats them. He’s had this happen before in a previous molt but I think it might be something else. And my bird usually scratches his head from time to time and he’s about 2 and half years old