I do not have any idea why, but my hens have decided to go on strike. I was gathering between 2 1/2 - 3 doz eggs a day. Over the past week or so it has dropped down to less than a dozen a day. What on earth could be causing this? I'm feeding laying crumbles, plus the usual treats of mixed bird seed, left overs.................My egg customers are not very happy. Have any ideas?