Nice free handbook that contains lots of secret activities.
This video shows how to fold the book:
You can use lemon juice, whole milk, or cream to write (or paint) an invisible message on a piece of white paper.
To reveal the message you need to heat the paper up. Get a grownup to help you by putting the paper in a hot frying pan and hold it down with a pot holder until the secret message appears.
Another method for revealing the secret message is to have an adult hold the paper over a hot incandescent light bulb and wait for the message to appear.
This is a great way for kids to talk to each other without anyone knowing what they are saying (caution to kids, many parents used this secret language when they were kids so they will be able to pick up on what you are saying pretty quickly – so ask them. “Hey mom and dad, did you talk Pig Latin when you were kids?” If they look confused then you are safe.)
It is so easy to learn Pig Latin since it’s really just saying English words in a different way. Here is how it works. Pick a word, take the first letter off the word and put it on the end of the word and then add “ay” to it. That’s all you do. Simple (or implesay in Pig Latin). With a little practice you can be really fast at this. Give it a try with your name and the names of your friends. For example: Robert becomes Obertray, Paul becomes Aulpay, Nancy becomes Ancynay, you get the idea. Have fun practicing this one with your friends and then you can talk with them in secret code without anyone else knowing what you are saying. How cool is that?!?
Every kid should know a little about Morse code. This language was devised so that messages could be sent using a Telegraph machine. You see, long before there were phones, people would send messages using a machine called a Telegraph which could make only two sounds: a short beep, which they called a dot, and a long beep which they called a dash. By using these two sounds in sequence, they communicated using Morse code. You can, too.
The absolutely, positively most important thing to know in Morse code is S.O.S. If you learn nothing else, you should learn these two letters. This is critical information for every kid and every Adult. Dot dot dot, dash dash dash, dot dot dot. If you are tapping it to someone it’s three short taps, pause, three long taps, pause, three short taps. Go on and give it a try. This has become the international symbol for help.
A good game to play is hangman using Morse code. Yes it’s difficult but it’s fun and good practice. Give it a try and see how much fun it can be.