The last week of March is used to make an origami April's Fool project. Some of you may know this model as a "Fortune Teller", or a "Salt Cellar", but today, we will use it as a "Cootie Catcher" (Fig 1).
To use this classic origami model as a Cootie Catcher, you must draw insects on some of the inner panels but not others. Note: "cooties" are technically the same as "body lice"; however, the term is often used to mean undesirable, small creatures such as bugs or germs.
Start the joke by showing your friend the inside of the Cootie Catcher with no cooties visible (Fig. 2). Use the Cootie Catcher to run through your friend's hair while snapping the Cootie Catcher open and closed. Then, show your friend the Cootie Catcher with the drawn insects visible (Fig 3). You can then declare, "April's Fool!" as you show the two orientations of the Cootie Catcher.
Option: continue the joke by putting the cooties back into your friend's hair: pretend to cough up the bugs onto the floor or back into your friend's head. Then, show the inside of the Cootie Catcher with no bugs: like magic, the bugs are gone.