Battery cages for laying hens were banned in the EU in 2012 but remain legal globally; they prevent all natural behaviour and represent one of the most severe welfare compromises in farming.
The battery cage represents the most extreme physical restriction ever systematically applied to a farm animal at scale. Birds were confined in spaces smaller than a piece of paper, unable to spread their wings, stand fully upright, move to avoid other birds, or perform any of their biologically motivated behaviours. The EU ban recognised this as incompatible with basic welfare requirements. However, the transition to enriched cages — which remain cages despite providing perches and a dustbathing area — means that most commercial laying hens globally still live in conditions that welfare science identifies as significantly harmful. The free-range and barn systems that allow genuine expression of natural behaviour represent a far better welfare outcome.