How to Make Homemade Spy Tools
Everyone knows spies are just plain cool. You may not be a real spy, but you can make some things at home that are just as spy-cool as the real thing. Whether you're writing a secret message or creating a secret hiding place, people of all ages can get involved. Hide things from your siblings or kids, add entertainment to a party for a birthday or Halloween, or just show off your spy knowhow.
Things You'll Need
- Lemon juice
- Small bowl
- Paintbrush
- Paper
- Heat source
- Thick book
- Sharp knife with a thin blade
- Pen or pencil
Instructions
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Invisible Ink
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1
Pour some lemon juice into a bowl.
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2
Paint a secret message on the paper with lemon juice and let it dry.
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3
Hold the paper up to a lightbulb or other heat source to see the message.
Book Safe
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4
Open a book about one-fourth of the way from the beginning and lay flat on a stable surface such as a table.
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5
Use a knife to carefully slice a square or rectangular hole in the pages on the right-hand side of the book. Leave at least one inch around the edges of the hole so the pages don't tear.
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6
Keep cutting until you have a large enough hole. The size of the whole will depend on what you are hiding. Leave at least one-fourth of the pages at the end of the book intact.
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7
Place your object in the hole and close the book.
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8
Put the book on a bookshelf and see if anyone notices the changes.
Ciphers
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9
Create a key for your cipher. The simplest way to do this is to assign each letter of the alphabet to a number. For example, A could be 1 and B could be 2. The numbers don't have to be in numerical order, nor do you have to use 1 to 26.
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10
Based on your key, write a message on a separate piece of paper.
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11
Make sure the message recipient has the key or your message will make no sense.
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12
Give the cipher message to the recipient. To make receiving the message more entertaining, hide it in your book sale.
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1
Tips & Warnings
Try other liquids besides lemon juice for your secret messages. See how they look different, depending on which liquid is used.
Use thin books for hiding thin things and fat books for larger objects.
Read a book about creating more complex ciphers.
Be careful when using a heat source to reveal invisible ink; you don't want to set the message on fire.
Small children should not use sharp knives; adult supervision is crucial.
