Hi, as Christine mentioned already, it could be from an ant bite, or it could be from her food bowls, or from having a wet chin after eating or drinking. What type of bowls do you use? Stainless Steel bowls are best, because plastic bowls hold bacteria, also the bowls should be washed daily. We rinse our bowls after their breakfast, and wipe them with a paper towel, and in the evening after their dinner, we put them in the dishwasher. I run my dishwasher at night, when I go to bed. Bullies are messy eaters and drinkers, and tend to slobber on themselves. Their face and chin and sometimes even their folds, can be wet after drinking water, and dirty after eating. You can use a paper towel to wipe dry the water after drinking, and use a unscented baby wipe to clean their face, chin and folds after they eat to ensure they are clean, and then dry them, so they don't become irritated from being wet.