The Oddest Closet Discovery

The name does most of the work. Even though it’s just a mechanical pop-out, the name primes your brain to expect “something alive”. In addition to the pop-out mechanism, the clacking or scraping sound created by the rattling version contributes to the overall shock factor.

My Experience With Envelope Pranks

As a kid, I was the recipient of an envelope prank (it wasn’t this specific one, but similar). As I opened the envelope and let out a noise I’m still not proud of, my cousin was laughing uncontrollably until he hiccuped. Five minutes later I asked him how it worked. That’s the typical sequence: jump, stare, laugh, learn, retaliate.

Why Only Works Once On The Same Person

First time around, it’s always great. Second time around, the victim thinks every envelope is potentially deadly. They’ll be hesitant to open an envelope and when they finally do, they’ll open it slowly while holding it at arm’s length. What used to be a fun prank becomes a perpetual warning, which is also entertaining in its own way.

What To Do If You Find One

If you want to render it harmless immediately, simply remove the rubber band. This is the “energy.” If the rubber band appears to be brittle or dried out, handle it carefully–as brittle rubber may snap unexpectedly.
If you wish to retain it, put it in a keepsake box. It is a piece of prank history and a good reminder that old jokes did not require much complexity to be funny–only a good timing and a victim who trusted the mail.

Why This Little Thing Remains So Well Remembered

The rattlesnake envelope prank is extremely small, incredibly simple and totally successful. It takes a completely ordinary event (opening a letter) and creates a story that people tell for decades. That is why it remains in drawers, closets and junk boxes for years after the laughter ends.