SIR – Since the ban on battery cages in 2012, many people believe that egg-laying hens are no longer kept in cages in this country. But unfortunately millions in the UK remain incarcerated in crowded, filthy cages simply to produce cheap eggs.

As revealed in Animal Aid’s latest undercover film, these “colony cages” offer little – if any – improvement on the traditional battery cages they have replaced and are almost indistinguishable.

Around half of eggs laid in the UK come from caged hens, and they are not just sold whole in supermarkets. Many are used in the catering industry and in processed goods such as cakes, quiches and fresh pasta, meaning many people are eating them without even realising.

Anyone wishing to see Animal Aid’s caged-hen footage for themselves should visit animalaid.org.uk or call 01732 364546.

Ben Martin, Animal Aid, The Old Chapel, Bradford Street, Tonbridge