We have a new bird feeder immediately outside the window where we sit and eat our lunch. It's designed so that only the smaller birds can access it, so blue tits, dunnocks and robins are the regular visitors - the not-very-bright chaffinch gang have yet to work out that there are big holes at both ends to allow access.
Those birds who have worked out how to use the feeder have been very pleased with it - that is, they were until a mouse moved in, causing some consternation.
The robin, who has been quite certain from the start that it is HIS feeder, almost bumped into the mouse, who had no intention of moving aside.
In fact, each time the robin came back the mouse was there, stuffing his cheeks with sunflower seeds, millet grains and other goodies and then scampering off, to reappear again within minutes to fill up with more.
In the end we had to chase the mouse away. He left very reluctantly, and was soon back again. Then we had a thought. Perhaps this wasn't one mouse, but a whole tribe of them.