The team collected sweat from hippos at a zoo and found that it contained two types of liquid crystalline structures. The banded structure, characterized by concentric rings that are comparable to wavelengths of visible light, makes it effective at scattering light, and the non-banded structure reduces the sweat's viscosity and allows it to spread more easily over the surface of the animal.
The red coloring is another of nature's impressive tricks. While at times giving hippos the appearance of bleeding, the secretion is simply akin to a form of "sweat," and is colored because of a pigment, which contains UV-absorbing molecules.
Our 2024 Coverage Needs You
Support HuffPost
Already contributed? Log in to hide these messages.