Crafts for Kids. Craft a Secret Message Card. Season 2 Episode 11 | 1m 44s. Secret messages and codes have been used throughout history — and by the Odd Squad — to keep messages private.

This means that decrypting the message can be as easy as holding it up to a light. ... Read more: Stretchy plastics hide secret pictures. Nature Communications DOI: 10.1038/s41467-017-01248-2 ...