Brianna has a very hearty, adult laugh at times. She does it randomly but she will keep doing it as long as you keep doing it back or until she gets distracted by something else. So excuse the loud laughter from me on these videos (I am so loud!) but she tickles me. One of the videos shows another favorite thing of hers to do - walk backwards! I do wish these videos were longer so you could get the full effect but they'll have to do.