Depending on what types of pens you favor, you may have noticed that the ones with caps (i.e, Bic pens) have little holes on the tops of the caps. If you've never noticed this before now, start taking in your surroundings, and watch this video to find out why the manufacturers leave those holes.
These holes aren't product defects — it's actually a strategic design to help someone who may (for whatever reason) get a pen cap stuck in their airway.
The hole prevents complete obstruction of the windpipe, and allows enough air to enter during the time it takes for you to dislodge the pen cap.
While you personally may not have an issue eating (and swallowing) your pens, this is an incredibly smart yet simple solution to the times those babies or dogs get a hold of your stash. Watch the video for more details about pen hacks and the "world's safest pen."