This quirky animated video from AsapSCIENCE explains the science of breasts in an entertaining way. The narrater answers questions like:  “Why is one often bigger than the other?” (and why it’s the left one), and “Why is breast cancer one of the most prevalent cancers in America?” (and why it’s on the increase).

MORE: 10 tips to help you lower your risk of getting breast cancer

The video also briefly explains other curiosities like why we love our breasts (even men), and how breastfeeding works.

MORE: Why breast cancer is such a common disease

Breast Cancer News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.