I decided to put down some rat poison. The stuff available to ordinary folks is not always effective now against rats, but it's all I have. I put it in a hollow by the fence where rats have dug under their way into the plot. I covered the tray with a plank across the top of the hollow. That should keep any rain off and keep all but vermin away, but there's enough gap for a rat to get in and fill his face. I'll see if any has been eaten tomorrow.
The purple sprouting broccoli is looking strong and I still have a few leeks left to harvest. It always looks forlorn at this time of year, but soon spring will arrive with new growth. Can't wait.