Rooting is one of the most strongly motivated behaviours in pigs, and welfare science reveals that enrichment must specifically match this intrinsic drive rather than simply providing novel objects that pigs investigate briefly and abandon.
Rooting motivation is a biological drive that cannot be eliminated from pigs through management, only redirected. When pigs cannot root in appropriate substrate, they redirect the behaviour toward pen fixtures, feeders, drinkers, and each other. Tail biting, ear biting, and pen destruction are not misbehaviours but expressions of unmet rooting need. Welfare science is unambiguous: pigs need manipulable organic substrate they can root and investigate, and this need cannot be met by chains, balls, or other objects that do not match the sensory and physical characteristics of natural rooting materials. Straw, compost, and soil are not a welfare luxury but a welfare necessity for pigs.