ABSTRACT
In this chapter we look at a class of interactions which are among the most fundamental in nature, that between two species, where one species exploits the other as a resource in some way. This can be between a predator and its prey, for instance between lynx and hare; a host and a parasite, for instance dogs and fleas; or between a host and a parasitoid, which can perhaps be thought of as an intermediate relationship between the first two, since the parasitoid lives within its host like the parasite but kills the host like the predator kills the prey. We consider a number of examples, including models of parasitoid wasps and worms with complex lifecycles and multiple hosts.
