Nesting Behaviour in Laying Hens and Housing System Design

The drive to find and use a nest box before laying is one of the strongest motivational states in hens, and housing systems that do not provide adequate nesting access cause acute distress.

Key Facts

Hens show significant distress behaviour — restlessness, pacing, vocalisation — when unable to access a nest box in the 1-2 hours before laying
The motivation to nest is so strong that hens will endure an electric shock to access a nest box rather than lay on the floor
Nest boxes should provide a dark, enclosed space of at least 35 x 25 cm with bedding material to satisfy hens nesting motivation
In aviaries, nest box access competition creates welfare problems when insufficient boxes are provided — one box per 5-7 hens is a typical standard
Floor eggs — eggs laid outside nest boxes — indicate inadequate access and cause additional welfare problems through hen walking on eggs and infectious disease risk
Hens using nest boxes show calmer behaviour and lower stress indicators compared to hens forced to lay in non-preferred locations

Welfare Considerations

Nesting before laying is not an optional preference in hens — it is a highly motivated behaviour driven by hormonal and neurological mechanisms that make its denial acutely distressing. A hen unable to access a nest box in the critical pre-laying period experiences something analogous to acute anxiety, expressed through restless pacing and vocalisation. This distress occurs multiple times per week throughout the hen productive life. Housing systems must provide sufficient nest boxes, distributed to prevent competitive exclusion, with appropriate dark, enclosed design and bedding material. The welfare case for adequate nesting provision is as strong as any in farm animal science.

What You Can Do

Choose eggs from certified systems with documented nest box provision ratios and design standards
Advocate for minimum nest box provision standards to be included in all cage-free housing transition requirements
Support research into optimal nest box design characteristics that best satisfy hen nesting motivation
Urge producers to monitor and publish floor egg rates as a welfare indicator reflecting nesting access quality
Learn to recognise adequate versus inadequate nesting provision when visiting farm open days or assessing egg certification claims