Did you know that octopuses have three hearts? Two pump blood to their gills, while the third pumps it to the rest of their body. When they swim, the heart that delivers blood to the rest of the body actually stops beating, which is why they prefer to crawl rather than swim—their way of conserving energy! Plus, their blood is blue due to a copper-rich protein called hemocyanin, which is more efficient than hemoglobin in low-oxygen environments.


