Insect blood is green, and gets its color from the plants it eats.
Octopuses use three hearts to keep their bodies well circulated.
Investigators shine a light on crime scenes mysteries with the help of luminol—a luminescent chemical that reacts with blood.
You've probably heard someone use the phrase "blood red," but have you ever wondered if all blood really is red in humans?
Many indigenous people live in areas of low oxygen concentration with few adverse effects. The big question is, how do they survive?
Although Everest had first been climbed in 1953, this was the first successful ascent to be made without supplemental oxygen.
The bacteria take nitrogen out of the air and make it available to other living organisms in an amazing process.
The legend of the vampire, Dracula, may have had its basis in a very real disease known as Hereditary Porphyria.
If blood is either red or blueish, depending on the presence of oxygen, why are bruises sometimes black, green, brown, or even yellow?
Scientists are developing a type of artificial blood for use in emergencies. Learn more on this Moment of Science.