Well I've had a lot of problems with theft and damage and last couple of years someone with a grudge who does little things to annoy e.g. cutting the string supporting my broad beans. The worst thing was watering glyphosate on my damson.....still fighting for life nearly two years later. I know who did it but can't prove it.
So this week when I got to my allotment and found cupboard doors I'd stored ready to make planters out of had been moved about I got cross and put them back. Two days later they'd been moved back, so I crossly moved them again and continued working. Noticed one of my near neighbours chickens out and scratching around near by, thought about some of the strange holes dug in some beds. Then the penny dropped! My neighbour is aware he has an escapee chicken and had used the doors to block the ways it could get on to my plot.....how thoughtful of him!
I put the doors back before I left. Then the chicken (actually a rooster on closer inspection) tried to come home with me when I left.