This edited volume focuses on parasite-host relationships and the behavioral changes parasites may trigger in their hosts. Parasites have developed strategies which enhance their chances to find a host to survive inside its body and to become most easily transmitted to one another. Many of these parasites influence the host's behavior by various mechanisms, so that the rate of their transmissions to further hosts becomes considerably enhanced in comparison to that of non-influenced specimens of the same host species. A broad number of recent studies elucidate more and more examples in an extreme spectrum of host-parasite relationships, where successful transmission and /or survival of a parasite inside a host is based on parasite-derived behavioral manipulations of the hosts. In the literature, an increasing numbers of papers appear which prove that these behavioral alterations are based on complicated psychoimmunologic, neuropharmacologic and genomically steered mechanisms. Researchers working in parasitology or behavioral sciences will find this work thought-provoking, instructive and informative.