I plonked myself in front of Brythen with three small dishes and a handful of biscuits, with a cheery cry of 'Right then!'. Brythen fled upstairs to his bed and hid. He is such a wuss!
Rosie, surprisingly, proved to be of sterner stuff. Once she realised that there were BISCUITS under the cups, she was all attention. Only a little encouragement was needed for her to nose and prod them.
I put a biscuit under the end cup, then took the cup off. She ate the biscuit.
Then I did the same thing, but I swapped the cups. She bopped the end cup with her paw, then tried to turn it over with her long pointy nose. I turned the cup over so she could see it was empty - and she continued to try to lift it up, convinced the biscuit must be hiding somewhere!
I wonder if she will get better at this. Maybe I should have started with two cups.