Octopuses have three hearts and blue blood
Two hearts pump blood through the gills and one pumps it around the body. Their blood is blue because it uses copper-based haemocyanin instead of iron-based haemoglobin to carry oxygen.
More animals facts
See all →Sea otters hold hands while they sleep
They float on their backs in groups called rafts and hold paws so they do not drift apart on the current. They also wrap themselves in kelp as an anchor.
Read the fact →Cows have best friends
Studies of dairy herds show cows form close bonds with particular partners and show measurable stress — higher heart rate and cortisol — when separated from them.
Read the fact →A group of flamingos is called a flamboyance
Flamingos are born grey or white. The pink comes from carotenoid pigments in the algae and shrimp they eat — a paler flamingo is usually an underfed one.
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