Dust bathing is a fundamental comfort behaviour for chickens that is completely prevented in cage systems and inadequately provided in many other housing types.
Dust bathing in chickens is not a minor preference but a deeply motivated behaviour with a clear physiological function: maintaining feather condition and managing ectoparasites. Hens deprived of dust bathing substrate accumulate frustration that eventually discharges as vacuum dust bathing — performed on bare wire or concrete with no functional outcome. This futile behaviour is a clear welfare indicator. Providing appropriate substrate is low-cost relative to its welfare benefit and is a standard requirement of higher welfare certification schemes. The barrier in cage and enriched colony cage systems is structural: there is simply no space or substrate available, and no amount of enrichment can compensate for this fundamental deprivation.