The spider that keeps a frog as a pet
There is nothing that unusual about keeping a frog as a pet, unless of course you are a tarantula. Generally when you think of pets, you assume that the owner is a human, having pets seems like a uniquely human trait but in fact there are a number of pet-owner relationships that do not include humans.
The spider with the pet frog has to be one of the most unusual though. Many of the bigger spider species prey on small frogs and many of the frog species prey on spiders, so it is not exactly a natural bond. However, there is one particular inter-species bond that does work. The Oklahoma brown tarantula will often keep one or more Great Plains narrow mouthed toads in their burrows as pets.
The reason the tarantula allows the toads to live in its burrow is that they eat the ants, which prey on the spider’s young. The spiders themselves struggle to kill ants and the toads are the natural predators of ants, making it a perfect match. The relationship is analogous to humans and cats. Cats were domesticated partly so they could protect our homes from rats and mice.
Humans are not the only animals to keep pets, though we are the only ones to keep pets that serve no specific purpose. Here’s looking at you, family goldfish.