Dust bathing is a fundamental biological need in hens that cage systems deny entirely and cage-free systems must actively provide for genuine welfare benefit.
Dust bathing welfare illustrates how behaviour that appears trivial from a human perspective can represent a fundamental welfare need for the animal. Hens deprived of dust bathing substrate perform vacuum dust bathing, going through the full behavioural sequence on a bare wire floor in an attempt to fulfil a motivational drive that cannot be satisfied in those conditions. This frustrated behaviour indicates that dust bathing motivation is intrinsic and strong, not merely a response to available substrate. The welfare assessment implication is that providing dust bathing opportunity is not a luxury enrichment but a basic requirement. Cage-free housing that provides good quality, maintained litter allows genuine dust bathing; enriched cages and poorly managed litter in cage-free systems often do not.