Thanatopolitics, most recently associated with the work of the Italian philosopher Roberto Esposito, is the politics of the deaths of some in order to sustain the lives of others. Primarily focused on the Nazi idea of perfection and wide distribution of biotechnical killing methods, and the division of people by 'race', this conceptualisation may also be applied to the modernist politics and techniques practised by many humans to kill animals such that they, the humans, may live better. Animal welfare science is changing, reflecting and informing the evolving philosophies and politics of animal lives, as well as new methods of assessing animal capacities, feelings and desires. The science of animal behaviour has greatly extended human knowledge of animal emotions and bonding. Ethology, a disciplinary area related to zoology, involves both laboratory and field research on animal social bonds, animal communication, animal culture and animal cognition.