Yael Petar
Henrietta the hen lived without special attention among 36,000 other chickens at Brendel Farm in Pennsylvania for 18 months - until the manager of the farm noticed that she had 4 legs.
"She is as healthy as the rest," says the owner of the farm, Mark Brendel, to The Daily American newspaper.
Brendel's 13-year-old daughter, Ashley, named the chicken Henrietta after Thursday's discovery. The bird has two normal front legs, and behind them another pair of feet. They have the same size as the front ones but do not function. The hen drags the other pair of legs behind her.
In 30 years of working on the farm, Brendel testifies, he has never seen a chicken with 4 legs.
No definitive reason is known for why such a mutation occurred, says Cliff Thompson, a retired professor of genetics at the University of Pittsburgh in Johannesburg. He says it could be a developmental mistake, like a sixth toe in a cat.
Brendel says he half-winkingly suggested his family put Henrietta up for auction online, but Ashley was adamantly opposed.
