Yes, stimming can be a part of ADHD masking behavior. Stimming, or self-stimulatory behavior, is often a way for individuals with ADHD to self-regulate and cope with overwhelming situations or sensory input. Some may start to appear more focused or engaged in their surroundings, which can be a form of masking their ADHD symptoms. Understanding and accepting stimming as a coping mechanism can be helpful for individuals with ADHD.