A hen travelled 90 miles in a lorry after sneaking aboard without anybody noticing.
The chicken travelled from Lincolnshire to Hertfordshire wedged underneath the trailer of an egg-delivery vehicle on June 18.
She was eventually discovered in Borehamwood by staff at a food delivery company, who called the RSPCA when they were unable to trace where the bird had come from.
Inspector Nicole Smith said: “The journey would have been a feat of hendurance for this little explorer but thankfully, the brave bird was completely unscathed.
“She was a little bedraggled from the wet and windy two-hour journey but she certainly wasn’t in a flap when she was found.
“The staff put her in a cardboard box where she made herself so comfortable that she laid an egg.”
The bird was placed with a local woman, Hilary Carlen, who has adopted birds from the RSPCA previously and gave her the name Henrietta.
Mrs Carlen, from Hertfordshire, said: “She’s a pretty strong hen. I don’t think most hens would have survived that kind of stress.
“She’s particularly robust as she seemed absolutely unruffled. She’s settled in well with my other six hens, three of which are also RSPCA rescues.”