Ive kept borders for a while now and to be honest, even out of out of well worked parents good lines etc you will still get a lot of litter wastage compared to other earth working breeds. There such a varied bunch some will be rarering to go at 12 months and some of thier litter mates wont even look at a rat in a trap at 18 months. Its a shame really, but there are still good working borders out there. In my opinion we all like different types, you find what suits you and stick to it, be it border, patterdale, lakeland bedlington they all have good and bad just some more than others