This weasel models the white underside look very nicely Konrad Wothe/Image Professionals GmbH/Alamy
Last Word is Â鶹´«Ã½â€™s long-running series in which readers give scientific answers to each other’s questions, ranging from the minutiae of everyday life to absurd astronomical hypotheticals. To answer a question or ask a new one, email lastword@newscientist.com
Why do many animals, such as mammals and birds, have white underbellies?
Herman D’Hondt
Sydney, Australia
Being lighter at the bottom than at the top is called “countershading”, and the main reason for it is camouflage. It is regularly found in animals like fish,…
