Wasps, like most insects have clear roles for each member of the colony. Basically, everybody makes sure the queen is doing OK making babies. Everything works like clockwork until a Svengali-like fly larva takes over a wasp and makes it do its bidding.
Wired reports that after burrowing into a wasp's abdomen the X. Vesparum fly takes control of the host and forces it to become its slave. Wasps that have been infected with the parasites are even forced to meet up so the parasites can reproduce.
Once a worker wasp with a female parasite is impregnated, it forgoes its instincts to serve and protect the queen and instead takes a place along side the queen. The infected wasps then wait until the queen is out foraging for food and starts dropping parasitic larva around the colony. The larva infect worker wasps and the weird cycle starts all over again. [Wired]