The pre-laying nesting sequence in hens is a highly motivated behaviour with significant welfare implications when it cannot be expressed. Nest box provision is a key welfare indicator.
The nesting motivation in laying hens is one of the most intensively studied animal welfare motivations, demonstrating clearly that hens experience genuine frustration when they cannot express this behaviour. Hens deprived of nest boxes show repeated attempts to find a suitable site, prolonged pre-laying unrest, vocalisation, and elevated stress hormones. The welfare science is unambiguous: laying hens require appropriate nest box provision as a fundamental welfare need. The transition from conventional cages (no nesting provision) to enriched colonies (some nesting provision) represented an important welfare improvement, though limitations in enriched cage nest box provision mean that hens in free-range or barn systems with proper nest access still fare better.