The latest hidden panda puzzle to sweep the internet takes the game all the way back to 1978. Tracy Lynn Heightchew, from Louisville, Kentucky, realised she had a real-life version of the challenge sitting in a drawer.
Years ago, she bought a photograph taken at the 1978 Junior Achievers National Conference in Bloomington, Indiana. Among the smiling young faces in the picture is, as might be guessed, a panda.
Heightchew posted the photo on Facebook and challenged people to spot the lonely bear hidden among the crowd.
The puzzle follows a string of similar viral challenges, including a panda concealed among a group of snowmen, and another panda mixed in with death metal fans in black and white make-up. A separate detour from the panda trend saw a cat hidden among a group of owls.
