My rat scratches his face and has sores. My rat scratches his face and has sores. Scabs are more likely to be caused by too much protein in the diet, allergy, or skin infection. Mites are only a possible cause. If it is mites.
Any vet can dispense less.
Diluted Ivermectin will curdle. Treat all rats that could have come in contact. Clean and disinfect cages. Repeat if nec. Take a little dab about the size that fits neatly on the flat part of a flat toothpick and smear it on the rats tongue.