As mammals on this planet, my girlfriends and I often exhibit very mammal-like behaviors. In addition to having warm blood, birthing offspring and producing delicious milk, we have other traits that bear a strong resemblance to a group of mammals in the fission-fusion society.
Raccoons are notorious for being bandits, engaging in gender-specific social behavior, and frequently meeting at feeding or resting grounds. At the end of the day, when the foraging (aka, fission) is over, they return home (aka, fusion).
When my girlfriends and I are not birthing and lactating, we have a tendency to gather on the stoop, hang out, imbibe, hunt for and consume food (restaurant/pub crawls), and, on occasion, commandeer a rocking chair, big wheel, etc. We, like the raccoons, are part of a fission-fusion society. Some, like Rick James, might say this makes us cold-blooded, but I believe science and Foreigner would disagree.