Dust bathing is one of the most strongly motivated natural behaviours in poultry, and its frustration in bare environments causes significant welfare harm.
Dust bathing in appropriate substrate is essential for hen welfare, serving thermoregulatory, feather maintenance, and motivational functions. Hens deprived of suitable substrate perform vacuum dust bathing — going through the motions on inappropriate surfaces — demonstrating the strength of the motivational state. Systems providing adequate litter for dust bathing have hens with better feather condition and lower stress. Free-range access to natural soil provides the most complete opportunity for this fundamental behaviour. Indoor systems must provide adequate, suitable litter depth to enable genuine dust bathing welfare benefit.