Sunday 5 February 2023

Tidbits #2 - Flea Bites

Another of my Weekend Wonders pieces from 2013 (updated for 2023). ____________________________________________________________________

The largest species of flea, Hystrichopsylla schefferi (the Mountain Beaver Flea) can grow up to 10mm in length. But most species of flea are no larger than 3.3mm long and many are far smaller. 


Photo: Dr Derek Hennen (via Twitter)

The average flea can jump approximately 197mm vertically and a distance of 330mm horizontally, which is pretty impressive. However, claims that ‘If a flea were the size of a man, it could jump over a skyscraper’ are not true. 

It’s all a matter of scaling in three dimensions. 

Imagine a cube 10mm square that weighs 1g. We can make a cube 20mm square by sticking eight of these 10mm cubes together. This cube is only twice the size of the 10mm cube … but it now weighs 8g, which is eight times heavier. 

If we now make a cube 100mm square, it would only be 10 times bigger than our 10mm cube but would weigh 1,000g (1kg). So, if we say that an average flea is 3mm tall and an average human is 172cms (1720mm) tall, our flea would need to be scaled up by a factor of over 570 times to be of a similar size. But it would be millions of times heavier, which would prevent it jumping any higher than you can. The only fact we can say is true is that, if fleas built their own flea-sized skyscrapers, they could probably jump over them. 


Interestingly, the game we call Tiddlywinks in the UK is most commonly associated with fleas almost everywhere else. The French call it Jeu de la puce (Game of the flea), the Germans call it Flohhopfspiel (The flea hop game) and the Portuguese call it Jugo da pulga (The game of fleas). 

Game of Fleas?

That would have been a very different TV series.

And, of course, we get the colour 'puce' from the French language. Who knew that their 1970s brown Austin Princess was the colour of a flea?

Oh, and you can read more about the history of Tiddlywinks here.

No comments:

Post a Comment