Mental Floss

BIG QUESTIONS





Dog whistles can make training easier.

The ultrasonic training instruments are easy to use. But there’s a dark history behind their inventor—and their initial purpose.

Jake Rossen




A fantastic blep.

We asked an expert to help us investigate the adorable causes of the tongue-lolling phenomenon.

Jake Rossen
















MRSA bacteria bound to a neutrophil, a type of infection-fighting white blood cell.

Public health officials are concerned that we could move back into a situation like that of the early 20th century, before antibiotics were discovered.

Tara Smith
They're not just for show.

Discover more about the origins of toenails—plus the real reasons why your toenails may be getting thicker and changing colors.

Matt Hoffman