I had some mites hatch and invade a nest with a setting hen once and I used a product called Scalex, it is a natural product with Pymethrum and is found at Pet Smart and such for caged birds. It worked really well. I Sprayed the hen cleaned the nest and sprayed the box. I put down new bedding and sprinkled DE in it and the area around the nest. These were a black Mite and not the tiny Northern Fowl Mites. Scalex worked great. The ones that hatched we could see moving around the nest. I would be very careful putting anything directly on the vent. You can put a pinch of 5% sevin on the side or on top and below the vent but all products I have seen caution you not to apply directly to the vent.
I agree that you should be concerned for your bird. I lost a rooster a few weeks ago due to anemia from having mites. It is not something you want to let go. Good Luck
I agree that you should be concerned for your bird. I lost a rooster a few weeks ago due to anemia from having mites. It is not something you want to let go. Good Luck