Hi I have an allotment too and tbh the best way is to dig out as much of the weeds and roots as you can, then cover with thick weed suppressant material and leave until spring. Then keep on top of the brambles etc. It’s hard work!
It’s a rat trap baby, and you’ve been caught! Sorry not at all helpful but couldn’t resist!😆 unfortunately you may have to stop feeding the birds for a while. My mum had the same problem and stopped feeding the birds. Rat didn’t return
😄 ha ha thanks, I know it’s a serious subject. I feed birds and I would be sad to stop. One thing we did when we saw a rat was to put a plastic sheet under the feeders and then get rid of the excess every evening. It was a bit of a chore but not seen a rat since 🤞