Just last week Dormouse pointed out , in her impeccable Glaswegian, that the van was "mingin" (in need of a clean) and that I hadn't cleaned it in four years, it was growing algae around the doors and weeds in the foot well. The hens obviously agree. Yesterday I left the doors open to "air" the interior and while I was away they did a valet service by foraging for tasty stuff on the floor.
This happens to all farm vehicles. Years ago I took the farm car, a Renault 4, for a service in Morpeth and the foreman asked if he could keep the contents of the foot well to fertilise his leeks.