Interspecies friendship raises intriguing questions about animal communication, such as how do different species learn to read one another’s signals and become friends? After all, many examples of friendships that cross the species divide involve animals with very different behaviors that arose from adaptations to diverse habitats.
Though interspecies friendship occasionally happens in the wild, it seems to be far more common when species are raised together in captivity. When housed together—whether in farms, sanctuaries, zoos, aquaria, or our homes—animals belonging to different species sometimes develop a common language that they use to establish the rules of their interactions, such as how to play together, when to give give each other space, and when it’s okay to snuggle. And then friendships develop.