Dust-bathing is among the most motivated behaviours in domestic hens, and its prevention in conventional housing causes measurable frustration and compromised welfare.
Dust-bathing represents one of the clearest examples in farm animal welfare of a behaviour so strongly motivated that its prevention constitutes measurable harm. Hens do not simply fail to dust-bathe when substrate is unavailable — they perform the movements on bare surfaces in a vacuum, expending effort on an unrewarding behaviour that cannot satisfy the underlying drive. The welfare interpretation is clear: this is frustration of a highly motivated behavioural system. Providing adequate, appropriate substrate is not an optional enhancement — it is a fundamental requirement of hen welfare. The quality and quantity of substrate, and its accessibility to all birds in the flock, are critical determinants of whether this need is genuinely met.