Behaviour-changing parasite

Behaviour-changing parasites are parasites with two or more hosts. They "cause changes in the behaviour of one of their hosts". This has the effect of improving their chances of reproduction. 
They make the first host more likely to be eaten by a predator. Then the parasite reproduces sexually in the predator. Examples can be found in bacteria, protozoa, viruses, and animals. 
Parasites may also change the host behaviour to increase the protection to the parasites or their offspring. The term "bodyguard manipulation" may be used for such mechanisms.
Example: a parasitic worm is eaten by an amphipod. The worm changes the behaviour of the host amphipod. The changes make it more likely that the amphipod is eaten by fish, where it reproduces. The induced behavioral change in the host thus leads to the parasite's increased success in completing its life cycle.