I've been raising chickens for 13 years now and for the first time I've got these new hens that have never started laying! I bought 4 black australorp chicks from Tractor Supply in late March. In September 2 of them started to lay. They look exactly the same so I'm really not sure which 2 are laying and they are extremely skittish. My other 2 older hens stopped laying in October so I'm only getting 2 small eggs a day. I've never had young hens that just never started laying. What could be wrong with them?