6 Secret Codes You Can Teach Kids

Do you want to know a secret? Speaking or writing in code with your grandchildren isn't just a fun way to pass the time – it's a wonderful activity for building their social and abstract thinking skills. And it's a great way to bond. So the next time you and the kids get together with secrets to share, try using one of these six clandestine languages or ciphers. They're easy to learn, appropriate for all ages, and just plain fun.

Made popular by the classic PBS children's program Zoom, Ubbi Dubbi is a nonsense language in which the syllable ub is inserted before each vowel of a word. For example, the word hat, would be written or pronounced hubat. A whole sentence might look like this:

English: That is a lovely hat, Grandma.

Ubbi Dubbi: Thubat ubis uba luboveluby hubat, Grubandmuba.

The Zoom website includes an Ubbi Dubbi-to-English translator to play around with. For more fun, try substituting other fragments for ub, like iz or arpy. It'll sound to non-speakers like you have a mouth full of marbles, but to you and your grandchildren, it will all make perfect sense.

To the uninitiated, Morse code sounds like beeping gibberish. But to those in the know, this elaborately spaced series of dashes and dots is a fascinating language, useful in wartime, at home, or as a potential lifeline in times of emergency. Usually attributed to painter Samuel Morse, Morse code was created in the mid-19th century as a way of communicating over the newly-invented telegraph. Each letter of the alphabet was represented by dots, dashes, or a combination of the two, and transmitted over the airwaves by an operator. The code was picked up by pilots during the 1930s, and became a major mode of naval communication after that, until it was finally, officially, retired during the 1990s. Today, Morse code is still popular among amateur radio operators, aviators, and cipher enthusiasts, who can draw, tap, or flash its letters to other aficionados across the globe. Find a Morse code translator here, or visit LearnMorseCode.com for a tutorial.

It's said that mirror writing, or the ability to write in reverse, is genetic – and that it comes naturally to just 1 in 6,500 people. One of those appears to have been Leonardo da Vinci, who wrote many of his personal notes from right to left. He could decipher his own pages, but others had to hold them up to a reflective surface. Today, you can see mirror writing on the hoods of emergency vehicles, so words like "AMBULANCE" can be read correctly in rearview mirrors. While some are born with the gift of mirror writing, it can also be learned through the ancient art of practice. Try it at home with a pen, a piece of paper, and a hand-held mirror, or follow the simple steps in this PBS Kids tutorial.

Substituting numbers for letters is one of the simplest written ciphers, with the digits 1 through 26 standing in for the ABCs (A=1, B=2, etc.). Using the code, you can compose long letters, short Facebook updates, or just find out if your phone number spells a word. For a slightly more complex code, try numbering the letters backward (A=26, B=25, etc.), or using multiple sets of 26 numbers (A=1 and A=27, etc.). If you don't quite have time to write a long letters-for-numbers message to your grandchild, check out this handy online text decoder.

If you've ever been told to "am-scray," you've heard Pig Latin. This altered language is so popular, Google has a Pig Latin search engine and you can even read several books of the Bible in it. To convert a word into Pig Latin, remove the first consonant, place it at the end of the word, and add the fragment ay. Duck becomes uck-day, and cupcake turns into upcake-cay. For words beginning with vowels, move the first vowel to the end, and add the syllable hay. For example, ostrich becomes strich-ohay. Pig Latin can be understood relatively well when spoken at a regular pace. To mystify friends and family, try speeding it up a little. And for extra credit, try memorizing a speech in Pig Latin using this online translator.

Some of the coolest codes don't require learning new languages or letter systems. In the case of invisible ink, all you need is special writing fluid and an appropriate surface. The concept behind invisible ink is straightforward: Using a top-secret compound, one person writes a message that can't be seen by anyone but the intended recipient, who knows how to make it appear. You can buy invisible-ink sets from toy or office-supply stores, or make your own at home using baking soda, lemon juice, milk, or white crayon.