Blood, sweat, and tears. Blood is often representative of something heavy — and yet, many of us don't even notice that it flows through our veins! Blood can symbolise family or be discussed during doctors’ appointments. However, blood is not that unique because we all fall under one of four categories: A, AB, B, or O. Your blood can also have a positive or negative rhesus factor (Rh). A rhesus is also a type of macaque monkey; however, no monkeys float through your bloodstream. That being said, we do have a common ancestor. Monkeys may not be in your blood, but they are certainly in your DNA.