Richard Feynman had a thing for ants

Written by Simon Garnier on August 8, 2015

Portrait of Richard Feynman - © The Nobel Foundation, 1965.
Portrait of Richard Feynman - © The Nobel Foundation, 1965

Today is the day Lisa flies to Africa for a couple months of field work. Among other things she will outfit local goats with GPS collars coupled with small microphones, that she just spent a month and a half patiently building in Swansea, where the SHOAL group of our collaborator Andrew King resides.

While in the train toward London Heathrow, she overheard a dad reading a story to his son, a story about ants. Out of curiosity, I asked her to enquire about the book the story was coming from. I was expecting some sort of children book, but was surprised to hear that it was actually “Surely You’re Joking, Mr. Feynman!”, a collection of anecdotes told by world famous physicist Richard Feynman.

I immediately fired up Google and quickly found the full text on Google Books. A few more clicks and here it was, the story of Richard Feynman and the ants.

It turns out that Feynman loved watching bugs, and ants in particular, and that he used is free time while at Princeton, and later Caltech, to perform simple experiments with them, in order to understand how ants navigate their environment. Isn’t it great?

Hereafter is one of these experiments, as told by Feynman himself. It is my favorite one, mostly because it ties in some work that we are currently doing in the lab. I hope you enjoy it as much as I did.

Many years later, when I was at Caltech and lived in a little house on Alameda Street, some ants came out around the bathtub. I thought, “This is a great opportunity.” I put some sugar on the other end of the bathtub, and sat there the whole afternoon until an ant finally found the sugar. It’s only a question of patience.

The moment the ant found the sugar, I picked up a colored pencil that I had ready (I had previously done experiments indicating that the ants don’t give a damn about pencil marks – they walk right over them – so I knew I wasn’t disturbing anything), and behind where the ant went I drew a line so I could tell where his trail was. The ant wandered a little bit wrong to get back to the hole, so the line was quite wiggly, unlike a typical ant trail.

When the next ant to find the sugar began to go back, I marked his trail with another color. (By the way, he followed the first ant’s return trail back, rather than his own incoming trail. My theory is that when an ant has found some food, he leaves a much stronger trail than when he’s just wandering around.)

This second ant was in a great hurry and followed, pretty much, the original trail. But because he was going so fast he would go straight out, as if he were coasting, when the trail was wiggly. Often, as the ant was “coasting,” he would find the trail again. Already it was apparent that the second ant’s return was slightly straighter. With successive ants the same “improvement” of the trail by hurriedly and carelessly “following” it occurred.

I followed eight or ten ants with my pencil until their trails became a neat line right along the bathtub. It’s something like sketching: You draw a lousy line at first; then you go over it a few times and it makes a nice line after a while.

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