I have now used a full tub of rat poison and started the next one. Each time the suggested dose of poison has gone completely. When I put down a tray with some in, the tray disappeared too. I feel like I'm feeding them rather than poisoning them. Something, maybe the rats, ate the last of our sweetcorn, so the stalks got pulled up and the patch dug over. I'm beginning to wonder if the rats are also under the shed, so rat proofing the spaces around it with wire netting or bricks might be on the cards. I wish I'd thought to do it when we put the shed up - it would have been much easier. I'm also wondering about the best way to stop creatures burrowing into the bank below the hedge. That really lies outside of our plot in the adjoining field, but a bit of netting might benefit us and the farmer.
This allotment is beginning to feel like a battlefield and a minor civil engineering site this year. I hope we get back to better times next year.