Dust bathing is a fundamental, highly motivated behaviour in chickens — its absence in conventional cage and barren barn systems causes chronic behavioural frustration.
Dust bathing welfare illustrates the concept of motivated behaviour — behaviours so fundamental that animals perform them even in the absence of the necessary conditions. A hen vacuum-dusting on wire is experiencing the frustration of an unsatisfied drive that her biology requires her to express. Providing substrate that allows proper dust bathing is one of the most direct and measurable welfare improvements possible in poultry systems. The evidence for its welfare benefit is robust, and the barrier to implementation is primarily economic choice rather than technical impossibility.