Meet the entrepreneurs using scrap rubber to fuel cars and make new tyres.

Each year, over a billion car tyres reach the end of their life.

They’re notoriously hard to recycle and present an environmental hazard if left to disintegrate out in the open.

But around the world, people are trying to clean up their cities by finding new uses for the mountains of rubber waste.

In Senegal, a young entrepreneur is turning them into artificial football pitches. In Zambia, an engineer is perfecting a way to turn these tyres into diesel. And in Canada, a company is making new tyres out of old ones using some very clever chemistry.

In California, butterflies such as the monarch are critically endangered as a result of habitat erosion, pesticides, and climate change. But many people are trying to save these beautiful insects.

We meet the scientists who are painstakingly rearing individual butterflies by hand and then releasing them back into the wild.

And at the famous butterfly groves on the coast, we see the first signs of recovery.

Presenter: Myra Anubi

Photo: A monarch butterfly (Getty Images)

Fish have favourite colours and dolphins hate high pitched noises.

Hospitals can make you sicker. It's a strange thought for places that also can make you healthier. But think about the constant noise, the distinctive hospital smell, the bright lights.

There's lots of evidence that most patients find hospitals themselves very stressful. This stress can lead to slower healing times or even a higher chance of being readmitted to hospital.

This week, we look at some interesting work happening around the world to try to improve the hospital environment.

We hear from people who are using nature to heal, are redesigning lighting systems and are blocking out the noise. And by learning what stresses humans out, we can learn a lot about how our bodies recover and heal.

When you get your hair cut, you probably don't think much about what happens to the bits that get chopped off.

But it turns out that rather than being dumped in the rubbish, hair can be put to all kinds of uses that can help clean up the planet and feed the people who live on it.

We meet a hairdresser who weaves the clippings into mats that get used to soak up oil spills.

Plus the young entrepreneur in Tanzania who's worked out how to turn human hair into a powerful crop fertiliser.

Presenter: Myra Anubi

Image: A man getting his hair cut

From an industrial-scale fly factory in London to farming bugs in the Madagascan rainforest, insects are being put to work all around the world.

The Prison Voicemail app connects inmates and their families, helping them stay in touch throughout a sentence.

Police in Iceland treat domestic violence differently.

Leaving an abusive relationship is hard, and many victims stay with physically or mentally hurtful partners, even after police get involved.

In Iceland, they focus their efforts on the first 24 hours after a domestic attack is reported.

This is the “window” in which survivors are most likely to give unfiltered evidence against their abusers and accept help leaving them.

Specialist police, social workers and child protection officers are swiftly sent into violent homes, and suspected offenders can be immediately removed. It’s a more hands-on approach than in most places, based on the view that domestic abuse is a public rather than a private problem.

Maddy Savage investigates how much the initiative has impacted prosecution rates and the wellbeing of families affected by this type of violence.

Image: Iceland’s top police officer Sigríður Björk Guðjónsdóttir

How do you get officers to step in to prevent other officers from harming the public?

Malaria kills more than half a million people per year. We meet the innovators who are using buildings, lights, genes and vaccines to fight the mosquito-borne disease.