It's the oldest trick in the book – a practical joke so ancient we thought it could survive these days only within the pages of the Beano.

Not so. Juvenile patrons outside the Barony Bar have been enjoying the sight of passers-by failing to retrieve a glittering pound coin. It is, of course, super-glued to the pavement.

Forget language, writing, abstract thought, technology, opposable thumbs and walking on two legs. In some respects we are no more sophisticated than trout.