Even though pigs are relatively new as laboratory animals, the human-pig interface goes back a long time and is dominated by the use of pigs for human consumption. Pigs are not strongly territorial, they merely defend resources within their home range. The diurnal rhythm of domestic pigs kept in semi-natural conditions is characterized by relatively long periods of rest/sleep and long periods of activity. Keeping pigs in barren environments can lead to behavioral problems, lack of stimulation, and poor welfare, but these issues can be improved by the use of environmental enrichment. Most pigs used for research are meat-producing breeds purchased from farmers or special-purpose breeds like the Gottingen minipig. The use of positive reinforcement training will develop a positive human-animal relationship with safe and positive interactions, where pigs voluntarily cooperate. Pigs that are routinely trained and socialized are less fearful of humans and they are expectant and calm when people enter the room.