Welcome to BYC. Not only do some folks have pet chickens, some have HOUSE CHICKENS. My friend Arline has had house chickens over 30 years - different breeds but generally bantams like silkies & seramas. She has had at the most 3 hen in the house at one time.
I thought I was getting chickens so I would have access to farm-fresh eggs, produced by happy. healthy birds. Turns out, eggs are just a by-product of having entertaining, amusing pets.
My queen chicken, a Buff Orpington named Honey, came to me as an adult more than four years ago. She rarely lays these days, but that hasn't diminished her value to me at all.
And. although I honestly need to get her outside full time, my house chicken, Dottie, spends her nights in a giant dog crate (it got too messy to keep letting her roost on the antique rocking chair) and knows the command, "Perch, Dottie." She will happily sit on my arm while I walk around the yard or the house, as if she is a tiny falcon.
Any chicken who quits laying is entitled to retire here, and I have a burial area just for poultry.