
was part of

Ellen D. and Dave were correct with the general idea that it was a mower. Congratulations to Wilma who was spot on identifying it as a robot mower. This one has been trundling round my 'lawn' for 4 hours each day throughout the Summer. It is one of the less complicated ones and therefore relatively cheap. No phone app needed. No GPS. No programming apart from choosing the length of time it needs to run. A wire has to be laid round the perimeter of its work area. It is random in its choice of direction to move and changes each time it reaches the perimeter wire. The wire is held down by dozens of plastic pegs and after a few weeks is invisible to the eye as it sinks in the surface of the ground.
For this week here is a close view

of what? If you would like to make a guess please leave it in the comments. They will be revealed, along with the answer, next Monday. As always, my thanks to all who have go.