CrowdScience listener Liana from Canada got in touch to ask about some very specific rocks she’d seen on an island in Indonesia – jagged, rugged and a very strange shape: hexagonal. They were in long columns, and clicked together like a jigsaw. But what are they, and how did they get there?

Across the world in the UK, CrowdScience listener Sarah emailed us to ask about the famous rocks of the Giant’s Causeway in Northern Ireland. What makes them so uniformly hexagonal?

Presenter Alex Lathbridge investigates, visiting the Giant’s Causeway to speak to geologist Dr Kirstin Lemon from the Geological Survey of Northern Ireland. She explains how this amazing landscape formed, and why the mythical rocks look the way they do today.

We also hear from Dr Alfend Rudyawan from Institut Teknologi Bandung in Indonesia about Liana’s intriguing rocks. Are these distant locations more closely related than you might think?

And we look to nature – because angular, uniform hexagons crop up surprisingly often. Professor Jean-Marc Schlenker from the University of Luxembourg explains why hexagons are much better than other shapes.

Presenter: Alex Lathbridge

Producer: Hannah Fisher

Editor: Ben Motley

(photo: Giant`s Causeway in Northern Ireland Stock photo- Credit: MANUEL FIL ORDIERES GARCIA via Getty Images)

Many plants need pollen from another plant of the same species in order to reproduce, but they don’t have legs so they can’t simply walk around looking for a mate.

As a result, many of them rely on animals to transfer pollen from one plant to another. They’ve developed a hugely diverse range of techniques to attract them, including their appearance, taste and smell. CrowdScience listener Alice in the UK wants to know how they have evolved to do this.

To try and answer the question, presenter Anand Jagatia goes trekking up a mountain in the Philippines, battling mud and leeches in the hunt for an incredibly rare flower. Rafflesia has evolved to look and smell like rotting meat in order to attract flies, so it’s the perfect example of a plant that goes to fascinating extremes to make sure it gets pollinated.

It only blooms for a few days each year, so to find it Anand is going to need the help of scientists at the University of the Philippines Los Baños and Lewis Barrett, Senior Botanical Propagator at the University of Oxford Botanic Garden and Arboretum.

Anand also visits the University of the Philippines Laguna Quezon Land Grant, a huge site containing more than 5,500 hectares of protected forest land. Professor Pastor Malabrigo Jr shows him a fig tree that has a fascinatingly gruesome relationship with its pollinator wasps.

So how did these amazingly diverse plants end up needing insect pollinators in the first place? Dr Kyra Krakos is a professor of biology at Maryville University and a research associate at the Missouri Botanical Garden in the United States. She explains to Anand that plants are surprisingly sexy – but how did they end up needing insects to survive?

Back in the Philippines, Anand’s guides have never actually seen the Rafflesia flower themselves, despite many attempts. So could this be the time they finally get lucky?

Presenter: Anand Jagatia

Producer: Dan Welsh

Editor: Ben Motley

With special thanks to Dr Chris Thorogood, Associate Professor of Biology at the University of Oxford and founder of the Community for the Conservation & Research of Rafflesia

(photo: Edited high angle view of Rafflesia on green gradient - Stock photo- Credit: Mohamed Tazi Cherti / 500px via Getty Images)

“What separates humans from animals, is an interest in the past”. That’s a 900-year-old quote from a textbook that Nigerian listener Taiwo came across, and he wrote to CrowdScience to ask if modern science would agree.

Most of us spend time thinking about the past, whether it is nostalgia for a bygone age or just wondering where we put the house keys yesterday. But is that just a human activity or do other animals also ruminate on their history and use it to make decisions? Taiwo wants to know if there is any evidence to show that animals have an interest in the past and if it matters to them.

Presenter Caroline Steel has a history of answering questions like this, so she sets out to find an answer. She meets researchers who have found evidence that animals not only remember past events, but use their memory for planning.

She talks to neuroscientist Dr Freyja Olafsdottir and discovers that some animals, including rats and mice, have the same brain structure for memory as humans.

She meets baby magpies in Professor Nicola Clayton’s laboratory in the UK and finds out about some of the very smart tactics jays use to hide their food from rivals, evidence that they’re using their memory to protect their interests.

She talks to psychologist Dr Gema Martin-Ordas whose research has shown that chimpanzees not only remember past events, but use what they’ve learnt in the future.

And she tests the memory of her own cat Oli, wondering if his ability to remember dinner time suggests that he is interested in the past too.

Ultimately it comes down to questions of consciousness, so as Caroline grapples with the idea that we can’t even be certain that other humans are genuinely conscious, what hope do we have of finding an answer for Taiwo?

Presenter: Caroline Steel

Producer: Jo Glanville

Editor: Ben Motley

(Photo: Cute clever cat with glasses reading a book. The cat lies on a stack of old books on a blue background. Credit:vvvita/Getty Images)

CrowdScience listener Rachel uses Bluetooth headphones on her cycle to work, seamlessly playing music from her phone without using wires. But how does this technology send information through the air?

To find out, Rachel and presenter Caroline Steel travel to Cambridge in the UK to meet telecommunications expert William Webb. He explains what Bluetooth signals actually are – and demonstrates why their properties are linked to the invention of leaky microwave ovens.

Caroline speaks to Jaap Haartsen, the inventor of Bluetooth, who reveals the hidden meaning of its logo, and what the name has to do with an ancient Viking king.

And she learns how a new flavour of “low energy” Bluetooth is having an unexpected application: helping ecologists like Damien Farine understand animal behaviour. Which leads her to an old tobacco barn in Switzerland, to meet researcher Bettina Almasi and her team – along with some very cute baby barn owls.

Presenter: Caroline Steel

Producer: Anand Jagatia

Editors: Ben Motley & Ilan Goodman

(Photo:Composite photo collage of hands hold phone device internet antenna connection technology bluetooth - stock photo- Credit: Deagreez via Getty Images)