When Hippos are upset, their sweat changes color. Nature magazine states that the secretion is made up of two unstable pigments - one red the other orange.

Hippo's 'magic' sweat explained. The really clever thing about hippos is that they produce their own sunscreen, in the form of a sticky reddish sweat.

The red secretion also has antibacterial properties, which work to protect the hippo from certain pathogens and accelerate in the recovery of wounds.

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