In fact, they may be most comfortable inside. Credit:Matt Golding "Chickens are related to forest-dwelling birds. They don't like open spaces," says Dr Charles Milne, who on Friday retired as Victoria’s chief vet. "Free-range can deliver huge welfare problems. "Instinctively as people, we anthropomorphise animals and think they must prefer free-range because we would." The RSPCA endorses both cage-free barn systems and free-range (it, of course, says battery cages are "horrible"). "We don’t say free-range is better," says Dr Kate Hartcher, the society’s scientific officer for farm animals. "They can be perfectly healthy and have good welfare in an indoor system."

Chickens like to be under cover - either in shaded outdoor areas on a free-range farm, or in a suitable indoor environment, Dr Hartcher says. Australians continue to swap cage eggs for free-range over concerns about the hens’ welfare. Free-range eggs made up 45 per cent of all eggs sold at major supermarkets last financial year, up 13.8 per cent. Meanwhile cage-free eggs, which come from chickens that live indoors but are not confined to small cages, make up only a tiny percentage of all eggs sold. Farmers wanting to label their eggs free-range are now required to run no more than 10,000 chooks per hectare of land, and must label their stocking density on the side of egg cartons. And the hens must have regular access to an outdoor range, and be free to roam and feed.

But some hens just don’t want to go outside. "A chicken does not really like running around in a field where an eagle can come down and go, ‘Thank-you very much,’ " says Associate Professor Tamsyn Crowley, who leads PoultryHub, an independent research institute based at the University of New England. "There is a push in Europe that free-range chickens should all have to go outside every day. And that clearly is not a good decision for welfare." Happy? Or nervous? Credit:Richard Cornish The chickens that lay our eggs are descended from red junglefowls, a small animal native to south-east Asia.

In the wild they live in small family groups under the canopies of thick rainforest. They make nests, find perches, and bath in the dust. They also maintain closely-monitored social hierarchies, known as pecking orders. A red junglefowl. Credit:Francesco Veronesi / Flickr We cannot ask them, and the research is not yet in, but chickens are probably happiest in small groups in a location they feel safe, says Professor Crowley – like a barn. The welfare of Victoria’s egg-layers will come under scrutiny with the passage of sweeping changes to Victoria’s animal protection laws and regulations promised by the state government. Dr Milne has been a key supporter of the incoming laws, and they will form part of his legacy.

Victoria’s chief vet Dr Charles Milne is retiring. His legacy will be new protection laws for Victoria’s farm animals. Credit:Joe Armao He believes they will significantly alter the way farming is done here. The big change: under the new rules, animals are considered as sentient beings with needs and rights that have to be respected. "Animals are not just property. An animal has feelings," says Dr Milne. "And we have a responsibility to safeguard their care. "Some procedures like mulesing will be consigned to the dustbin of history. We will see a change in the way animals are reared. The future will be completely different." World Animal Protection recently ranked Australia’s animal welfare standards at a C – comparable to India, Malaysia and Brazil, and well below the standards of the UK, New Zealand and Chile.