It throws up that bacteria into the rodent it's living on and then that rodent's going to die. And then the flea has to find somewhere else to go. And if there's no humans around, it's kind of all good. It really doesn't bother anybody. But once the rats come into contact with humans, then the fleas are going to jump on the humans and then we have ourselves an epidemic because that's at the heart of bubonic plague. Because once the flea jumps on the human, it's going to enter the lymph node of where it's going into. That's going to create these huge swellings on the armpits, on the groins, on the lymph nodes of the human body.