Sterile hen?

[tralfaz]

One of my hens have yet to start laying and her mates, which are all the same age at 6 months, have been laying for about 5 weeks. Now all but her are producing eggs every day for about a week. When should I be concerned and are there other issues I may need to monitor? I read here about some type of blockage, is that a possibility?

 

[rosemarythyme]

Some chickens take longer than others to start up. 6 months isn't unusally long. What breed is she? Does she look like she'll start laying any time soon (red, plump comb, squatting if you come close, sudden interest in nest boxes)?