Some people like to keep tarantulas as pets. Others might prefer to keep frogs. What would you say about a tarantula that keeps a frog as its pet?

As strange as that may seem, it is actually quite common. Many varieties of tarantula have developed a special relationship with a tiny species of frog known as Chiasmocleis ventrimaculata. This 3 cm frog is easy prey for the abundant predators of the South American rainforests where it lives. To protect itself, the frog likes to hang out with the tarantula — a spider so large and fearsome in appearance that even large predators are known to stay clear.

Why doesn’t the spider gobble down the frog for a quick snack? It turns out that the frog’s favorite meals are generally the insects that like the eat the eggs of the tarantula. The relationship works out so well that in areas where the frog is known to live, you rarely will see one of them without the other.