From The Telegraph
Wildlife expert Chris Packham sneaked rock star David Bowie's song titles and albums into BBC show Springwatch - 49 times in one series.
He admitted slipping the song titles discretely in to the show had been a challenge.
But co-presenters Michaela Strachan and Martin Hughes-Games as well as the production clue had been completely unaware of what was going on.
He said: "It's not something that's planned. The show is live and not scripted.
"I don't know what my co-presenters are going to say so I have to have the songs in my head and as we are talking I need to find a way to fit them in.
"I don't look up or research titles beforehand either so it needs to be a band or artist that I know well.
"It presents me with a challenge and that's ultimately what it's about. It keeps me focused.
Video montage edited by John Slatex. All content: BBC.