Environmental complexity including varied terrain, objects, and substrates supports pig exploration behaviour that is fundamental to psychological welfare.
Environmental complexity addresses a fundamental cognitive need in pigs for varied and novel stimulation. Barren concrete pens provide no complexity and generate the chronic boredom that drives stereotypic behaviour and aggression. Complex environments including rooting substrates, objects to investigate, and varied terrain engage pig curiosity and exploratory drive. Complexity provision is not merely enrichment but a basic requirement for psychological welfare in an intelligent species.