Ig Nobel Prizes 2024: 'Kamikaze' Pigeons, Dead Fish That 'Swim' Upstream, and More

An experiment that trained pigeons to pilot bombs and another that explained how dead fish can swim upstream are among a slew of bizarre research that was awarded Ig Nobel prizes this week.

The Ig Nobel prizes, awarded this week, celebrate bizarre research that sparks an interest in science. Here are some highlights.

An experiment that trained pigeons to pilot bombs and another that explained how dead fish can swim upstream are among a slew of bizarre research that was awarded Ig Nobel prizes this week.

Organised by the magazine Annals of Improbable Research, the annual prize ceremony held at Harvard University celebrates hilarious research that spurs interest in science. And the awards are presented by genuine Nobel laureates.

Among the other eight winners was a team that showed how the hair on your head swirls in a different direction depending on whether you live in the Northern or Southern Hemisphere.

A study showing how painful side-effects can make fake medicine more effective, and another revealing a flipped coin is more likely to land on the same side it started on, also got a gong.

As did scientists who popped paper bags next to a cat standing on a cow, and those who revealed how mammals can breathe through their anus — in an emergency.

'Kamikaze' pigeons

The psychologist and inventor BF Skinner is best known for his theory of "operant conditioning", that says you can use rewards to teach behaviour.

It's an idea he put into practice in the 1940s, when he trained pigeons to guide bombs to their target.

Dr Skinner obtained pigeons for his experiments from racing fanciers and a farmer.

(Getty Images: Bettmann/Contributor)

One of Dr Skinner's daughters, Julie Vargas, a behaviour analyst herself, explained:

"During World War II, my father wanted to help the war effort.

"Pilots were having a hard time hitting enemy ships. They had to get so low to hit the target properly they often lost their lives."

Enter the top-secret Project Pigeon.

While pondering missile guidance systems, Dr Skinner became inspired by the deft manoeuvring of birds in the sky. 

He thought they could be used to pilot bombs and initially tried training crows, "but they were too aggressive", Dr Vargas said. 

So Dr Skinner decided to train a set of "kamikaze" pigeons, and built a contraption that fitted on the front of a missile to accommodate avian pilots.

He then used movies to train each pigeon to steer a missile towards a ship. The bird had to peck repeatedly on the image of a ship as it got bigger in the screen (as it would in real life as the bomb fell through the air) to be rewarded with food.

Despite initial scepticism, Dr Skinner got several grants for his feasibility study.

Although electronic guidance systems won out in the end, the same kind of methods have been used to train birds to identify survivors at sea, Dr Vargas said.

Dr Skinner's work was eventually declassified and described in a 1960 issue of American Psychologist where he wrote:

The ethical question of our right to convert a lower creature into an unwitting hero is a peacetime luxury.

In recognition, his work was awarded the 2024 Ig Nobel Prize for Peace.

How dead trout 'swim'

As a child, James Liao, a biologist at the University of Florida, used to ponder why some fish love swimming behind rocks in a stream.

Fast forward to the 21st century and he found himself defrosting a dead trout to find out.

This was part of an experiment where he first analysed the behaviour of live rainbow trout in a tank full of flowing water. To simulate a rock in a stream, he placed a cylinder in the tank upstream from the fish.

The trout swam forward but appeared to have a ultra-relaxed and passive swimming style.

"It was this weird sashaying movement that looked like a flag flapping in the wind," Professor Liao said.

He had a hunch that it would be useful to look at what happened when he tied a dead trout downstream from the cylinder instead.

Lo and behold, the deceased fish also "swam" forward against the flow.

The dead fish looked just like the live fish swimming, Professor Liao said: "They were almost indistinguishable." 

His analysis showed that the energy for the movement of the fish — dead or alive — came from swirling eddies created by the presence of the cylinder.

As the eddies hit the body of the fish first this way then that, the animal moved forward against the flow without having to use its muscles.

Professor Liao likened the movement to surfing instead of swimming, or changing the angle of a sail to catch the wind and tack across a bay in a boat.

It means fish use the energy of water swirling behind rocks to swim upstream, and is what helps migratory species such as salmon cover long distances up rivers and streams, Professor Liao said.

Professor Liao was awarded the 2024 Ig Nobel Prize for Physics.

Hair in the hemispheres

There's been a lot of debate over the decades whether water spirals down the plug hole one way in the