7D20.10-Mousetrap Demo


Video: Watch this demo

Description: This demonstration models the cascading aspect of a Nuclear Reaction. When all the traps are set, just throw in the mouse.


  • Plastic box (also used for break the beaker)
  • Lot’s of mouse traps
  • Twice as many corks
  • Little rubber mouse

Setup Procedure:

  1. Set this up as close to the classroom as possible.
  2. Take a mousetrap and set it. Place 2 corks on it. Gently place it in the plastic box.
  3. Repeat until the whole box is filled (see picture).
  4. Be aware of how you set the traps, so in case it goes off, it won’t hurt your fingers.
  5. When putting the corks on, position them in a way that they will not get jammed when the trap goes off.
  6. Also, be very careful when wheeling it into the classroom (if you can, setup in the classroom prior to the class).
  7. Some professors like the apparatus to be covered with a black cloth until they use it.
  8. Try and keep it out of the way of high traffic areas.
  9. When the professor is done, use a stick to poke around to set off any traps that did not go off.

Demonstration Procedure:

  1. Open the foam flap.
  2. Throw the mouse in and quickly close the foam flap (so things don’t fly out).
  3. Chaos follows for 1-2 seconds.
  4. Explain how this ties in with a nuclear reaction.

Setup Time Warning: This demo can take a very long time to setup, especially when a trap goes off accidentally and sets all the rest off.
Allow plenty of time, and go slowly. The little extra time put into caution is worth it here.