Many birds do in fact build their nests next to the nests of wasps, hornets, and bees, mainly for protection from predators. The birds don't bother them so they don't bother the birds. Predators, who may be looking to eat an egg, a baby bird, or even an adult, will inevitably disturb the wasps and will get what's coming to them.
This doesn't appear to have worked for Josh, though. I'm not sure if he ended up like that because of the wasps or because of a predator that the wasps didn't protect him from. I think I prefer the ambiguity.