Principal Hart needs a detective. Turn your sound on.

Lessons you need for this case

The six notes in this case are written in six secret codes. You must have finished all six code lessons to solve the whole mystery. If you skipped one, go back and learn it now.

Check the box next to each lesson you have finished.

    Check all six lessons to open the case.

    How this case works

    1. Read about the case and meet the eight suspects.
    2. Crack the six notes. Each one is written in a different code, and nobody will tell you which code is which.
    3. Answer three questions. Who is leaving the food? Why are they doing it? What food is coming next, and where?

    Be careful with step 3. A wrong answer locks the answer box for 3 minutes. Guessing will not work. Cracking the notes will.

    My badges

    Your work saves on this computer.

    Teacher note

    Answers are inside. Enter the teacher password.

    What is going on

    It started on Monday at Juniper Elementary. Somebody left a plate of crackers and honey on the floor by the library door. By lunch, a long line of ants was marching in from the playground.

    On Tuesday it was chips by the music room. On Wednesday, apple slices by the drinking fountain. On Thursday, cereal by the art room. Each day the ants came back, and each day there were more of them.

    This is a big problem. Principal Hart is allergic to ant bites, so she cannot go anywhere near them. On Friday morning, ants marched right into her office. Now she is running the school from the nurse's room, wearing a beekeeper hat.

    What we know

    The foodIt is never a mess. It is always set out neatly on a clean paper plate.
    4
    The flagsEvery plate has a toothpick flag with a number on it. So far: 1, 2, 3, and 4.
    The antsThey march in from the playground and go straight to each plate. Buzz the bug sprayer has been called five times.
    The notesSix pieces of paper with strange writing, found near the plates. All six were written with the same green pen.
    A cookieFound in Milo Baker's pocket. A trail of crumbs followed him all the way down the hall.

    Principal Hart says: "Milo leaves crumbs everywhere he goes. It is Milo. Please catch him before the ants catch me."

    The timeline

    • Monday. Plate 1. Crackers and honey by the library door. Ants by lunch.
    • Tuesday. Plate 2. Chips by the music room. Buzz sprays the hall.
    • Wednesday. Plate 3. Apple slices by the drinking fountain.
    • Thursday. Plate 4. Cereal by the art room.
    • Friday, 8:30 AM. Ants march into the principal's office. Odd. Nobody left a plate there.
    • Friday, 9:00 AM. Principal Hart moves to the nurse's room and puts on a beekeeper hat.
    • Next Friday. The school science fair. Principal Hart is supposed to hand out the ribbons.
    A word to know: allergic. When someone is allergic to ant bites, even one bite can make them very sick. That is why Principal Hart must stay far away from the ants, and why this case cannot wait.

    Eight people are on the list

    Each of them has a reason, or was near the plates this week. An alibi is proof that you were somewhere else when it happened. Look at who has one.

    Principal Hart says: "Read them all if you like. But I keep coming back to Milo. Follow the crumbs, detective."

    The six notes

    Every note has a secret message. First work out which code it is. Then crack it. The keys are in the Code toolkit tab. You need all six notes to answer who, why, and what comes next.

    Notes cracked: 0 of 6

    Caesar Wheel Review the lesson

    Every letter slides the same number of steps down the alphabet. Find the secret number, then slide the strip. Look up each code letter on the top row. The real letter is right under it.


    Pigpen Cipher Review the lesson

    Each letter is drawn as the shape of the pen around it. Shapes from the second grid and the second X have a dot. Use this key for this case.

    Polybius Square Review the lesson

    Every letter is two numbers. The first number is the row. The second number is the column. I and J share a box.

    Spartan Scytale Review the lesson

    The letters are not changed. They are only mixed up. The message was written on a strip of paper wrapped around a rod. Wrap the strip around a rod of the same size and the words line up again.


    Read across each row, starting at the top. If the rod is the wrong size, you get nonsense.

    Rail Fence Cipher Review the lesson

    The letters are not changed. They are written in a zigzag on the rails of a fence, then read one rail at a time. Here is HELLO WORLD on two rails.

    H . L . O . O . L . . E . L . W . R . D

    Read the top rail, then the bottom rail, and you get the code: HLOOL ELWRD. To crack one, count the letters and split them into a top rail and a bottom rail. If the count is odd, the top rail gets the extra letter. Then zigzag: top, bottom, top, bottom.

    Tap Code Review the lesson

    Every letter is two sets of taps. Count the first set to find the row. Count the second set to find the column. C and K share a box.

    Two taps, then three taps, means row 2, column 3. That is the letter H.