Sometimes if the parasite moves from host to host as part of it's life cycle, and this can include aiding the death of one host. An example of this is a parasit

Sometimes if the parasite moves from host to host as part of it's life cycle, and this can include aiding the death of one host. An example of this is a parasite that causes frogs to grow extra legs so that they are easier to catch for birds. The parasite then transfers to the bird, where it can lay it's eggs. http://phenomena.nationalgeographic.com/2013/02/13/a-flurry-of-frog-legs/ http://phenomena.nationalgeographic.com/2013/02/13/a-flurry-...