Introduction -- Parasites: an own world of cross reactions with their hosts -- Trait-mediated effects of parasites on invader-native interactions -- Cooperation or Conflict: Host manipulation in multiple infections -- Can parasites change thermal preferences of hosts? -- Host Manipulation by Toxoplasma gondii -- The brain worm story -- The bodyguard phenomenon -- Remote control: parasite induced phenotypic changes in fish -- Virus-induced behavioural changes in insects.