My powers of observation and education have now been vindicated. Hedgehogs are definitely visiting our garden. We borrowed a trail cam from friends of ours, and have managed to record them on film.
For some time I believed that I had seen hedgehog droppings in the garden, but because they are nocturnal animals I wasn’t able to catch them at it. So I constructed a little shelter, along the lines publicised by a hedgehog rescue charity, and for several nights I was putting out food, as advised by a friend. It was clear that whatever was taking the food cannot have been squirrels, because they are diurnal and hedgehogs are nocturnal animals. An attempt to get footprints from the visitors was inconclusive. Finally, friends of ours told us that they have a trail-cam, on which they had managed to film hedgehogs in their own garden. After a couple of experiments I have managed to get some good shots of our little visitors in action. I’m delighted!