Animals feed
Green fur
Yes. Green algae grow in the fur of sloths, especially three toed sloths, giving them a greenish tinge. Their hair is grooved to hold water, creating a tiny ecosystem.
3
Octopuses have three hearts: two supply the gills and one supplies the rest of the body. Their oxygen-carrying protein contains copper and turns blue when oxygenated.
Cubes
Wombats produce distinctly cube-like droppings, shaped inside the intestine rather than by a square opening. Research links the shape to differences in the mechanical properties of the intestinal wall.