During the first wave, the feline critters traveled from the Middle East to the eastern Mediterranean, an area known for its fertile lands. This finding supports the long-held belief that farmers—in desperate need of rodent control—encouraged the spread of cats. The next wave—which occurred thousands of years later—started in ancient Egypt, where cats were worshipped, and moved to Africa and Eurasia via seafarers. Researchers notably found that the DNA from an Egyptian cat matched that of a feline found at a Viking site in Germany. It is believed that Vikings—along with other mariners—took cats on ships in order to control rats and mice. These findings are not surprising, given the presence of cats in Norse mythology. The goddess Freyja—who was in charge of love, fertility, battle, and death—traveled in a chariot pulled by two large cats.

In fluorescence, light is absorbed and then reemitted. Many sea creatures fluoresce, but among land animals, only some parrots and scorpions do this. (Creatures such as fireflies are bioluminescent and generate their own light through photochemical reactions without having to absorb it first.)