This month will see thousands of people take to streets around the world to test their feats of endurance. It’s marathon season. And this week, we’re looking at the science behind what keeps you running.

This week, a court in Kenya sentenced four men to either a year in prison or a fine of £5,800 for trying to smuggle 5,000 ants out of the country. The contraband included highly-valued ants like the giant African harvester ant, and it’s believed these ants were intended for exotic pet markets abroad.

But all this talk of ant smuggling got the Unexpected Elements team feeling antsy to talk ants!

We learn about the earliest ants who lived among dinosaurs, ants that can sniff cancer, and ants who were sent into space!

Then we take a turn from ants to anteaters and talk to Mariella Superina from the International Union for Conservation of Nature about the different adaptations and skills needed for anteaters to successfully eat ants.

Plus, we discuss plant smuggling and ant wrangling, both unexpectedly dangerous ventures.

All that, plus many more Unexpected Elements.   

Presenter: Marnie Chesterton, with Leonie Joubert and Godfred Boafo

On 21st April 2025, Pope Francis, the head of the Catholic Church, died.

His funeral took place on 26th April, with thousands of mourners crowding into St Peter’s Square to pay their respects.

Following the death of a Pope, there are centuries-old traditions and rituals that must be followed, and that got the Unexpected Elements team thinking about the science surrounding loss.

Next, we are joined Carl Öhman from Uppsala University in Sweden, who reveals what happens to our data when we die and why we should care about it.

Plus, we discuss the precious materials hiding in our old devices, and find out whether animals mourn.

All that, plus many more Unexpected Elements.   

Presenter: Marnie Chesterton, with Andrada Fiscutean and Edd Gent  

This week the Unexpected Elements team left our windowless BBC studio and paid a visit to the CGIAR conference in Nairobi, Kenya.

In this episode, we find out about the Kenyan invention that’s pulling clean, safe water from thin air, before discovering what makes Kenyan coffee taste so great.

Next, we hear about the problems with burning charcoal and the ways in which briquettes could offer a cleaner, more sustainable solution.

Plus, we’re joined by Joyce Maru, the regional director for Africa at the International Potato Centre. She reveals the science behind the orange-flesh sweet potato and explains how it could improve livelihoods and boost health across Africa.

We then hear about the story of the two Kenyan inventors who have created a Swahili-speaking robot.

Finally, our panellists go against the clock in our Kenyan Science Showdown.

This week is the Christian celebration of Easter, which sent the Unexpected Elements team scrambling for egg-related stories.

First up, we find out about the rise of a vegan egg substitute.

Next, we discover how to cook the perfect boiled egg, according to science.

We then turn our attention to climate change, and find out how it is affecting the breeding patterns and nesting behaviour of sea turtles.

Plus, we are joined by Dr Luis Welbanks, who tells us about a nearby exoplanet that reeks of rotten eggs.

Finally, we delve into the science behind IVF.

All that, plus many more Unexpected Elements.

The Aurora Borealis – also known as the Northern Lights – won’t be at their peak activity much longer, and the Unexpected Elements team dreams of going north to see them. And that has got us looking at the science of navigating our way north!

We hear about how humans have been using the sky to navigate for millennia, and we learn about how relying on GPS may be impacting our memory ability.

And while humans use maps to get around, how do animals know where to go on their long migrations? To find the answer, we speak to Dr Kayla Goforth at Texas A&M University who studies exactly how sea turtles and monarch butterflies innately know how to navigate the world around them.

We also learn why polar bears keep themselves ice-free, and we hear old records of the first men to reach the North Pole.

All that, plus many more Unexpected Elements.

Presenter: Caroline Steel, with Andrada Fiscutean and Phillys Mwatee

On World Rat Day, we’re getting ratty! We look at the biology behind the eternal struggle between rats and rat poison, and we hear about rat-on-rat warfare and other forms of pest control.

We don’t play games when it comes to rats, but we know someone who does. Dr Michael Brecht from the Humboldt University of Berlin tells us how he played hide-and-seek with lab rats and what that tells us about the behaviour of play.

On the topic of ‘rat’ behaviour, we are joined by Dr Zach Berry from the University of Southern California to talk about the psychology behind ratting people out in the workplace, testing the loyalty and morals of the Unexpected Elements team.

And speaking of rats in the workplace… we hear a first-hand report on whether African giant pouched rats might just be better staff members than humans when it comes to detecting tuberculosis at APOPO labs.

All that, plus many more Unexpected Elements.

Presenter: Anand Jagatia, with Tristan Ahtone and Christine Yohannes

April 1st is notorious across the globe. Renowned for being a day of practical jokes. And it’s no different here on the BBC World Service.

Mischievous elephants, the secret to fool's gold and one of the biggest scientific hoaxes in scientific history.

From the Magic Circle to the Magic Lab, the psychology underpinning why we humans are so delightfully easy to trick with Professor Gustav Kuhn.

And a question sent in from one of you: if two people eat the same thing for breakfast, does the same thing come out the other end of both of them?

Prepare for a prank or two on Unexpected Elements.

Or as they say in Finland, ‘Aprillia, syö silliä, juo kuravettä päälle’, which translates to ‘April trick, eat herring, drink muddy water afterwards!’

Presenters: Caroline Steel with Camilla Mota and Phillys Mwatee

Five years ago, people around the world were enduring COVID lockdowns as we attempted to prevent the spread of the virus. Today, many of those who caught COVID-19 are still suffering from lingering symptoms, including a loss of their sense of smell. And that got the Unexpected Elements team thinking about all things olfactory.

First up, hold your noses as we investigate the two chemicals that make up the scent of death.

Next, are you prone to telling lies? Well, research suggests that your nose might give you away!

We then turn our attention to the cinema to find out more about the chemicals you release during a scary film.

We’re also joined by chemist Professor Matija Strlic, who reveals how he can detect aromas in ancient Egyptian mummies and – crucially – tells us why he wants to do this.

That, plus many more Unexpected Elements.

Presenters: Marnie Chesterton, with Kai Kupferschmidt and Affelia Wibisono

It’s the month of Ramadan, when Muslims across the world fast between dawn and sunset in the belief that it will bring them closer to Allah. And this has inspired the Unexpected Elements team to turn their attention to all things fast.

First, we explore the latest research around intermittent fasting.

Next, we contemplate a new way to relax by harnessing the time-distorting power of black holes.

We then find out why deserts in South Africa are spreading at an alarming rate.

Plus, we’re joined by Dr Claire Lee, a particle physicist who works with the Large Hadron Collider at CERN. She explains how she and her colleagues accelerate particles to phenomenal speeds, how they detect these particles when they collide, and what this can tell us about the origins of the universe.

That, plus many more Unexpected Elements.

Presenters: Marnie Chesterton, with Tristan Ahtone and Leonie Joubert.