Tarantula Wasps - yep that's what they are actually called. Beautiful looking - but they are awful - to tarantulas, which I felt pity for until later that night when I met one. Anyways, what they do is sting the tarantula, it becomes paralysed. The wasp then lays it's babies in the tarantula, they hatch, and then eat the spider from the inside out :( What an awful way to die :(