Dustbathing is a fundamental behavioural need in chickens; its absence in barren environments causes frustration and poor feather condition that affects millions of birds.
The dustbathing sequence — fluffing feathers, side-lying, scratching and rolling — takes 20-30 minutes and appears to function as both a physical (feather maintenance) and psychological (positive affect) behaviour. When hens are denied suitable substrate, they perform the full motor sequence in thin air or on wire — a behavioural frustration that persists lifelong. Research shows that hens deprived of dustbathing show higher aggression and feather pecking, both serious welfare concerns.