This is the Happy Pod from the BBC World Service.

Hello, I'm Oliver Conway, and in this edition...

You know, she was saving life, she saved a lot of lives.

We meet Carolina, the rat who's retiring after using her sense of smell to detect tuberculosis,

the new vaccine providing hope in Uganda's fight against malaria.

It's estimated that this vaccine rollout will prevent around 800 cases of severe malaria every day.

The man who set a world record for running barefoot on ice.

They help me understand myself more.

I wish everybody to have a chance to get connected to ourselves.

And...

The monkeys that have been crowned the best yodellers in the world.

But we begin with a remarkable rodent that saved thousands of human lives.

Carolina is a rat who spent years detecting cases of tuberculosis.

Local clinics in Tanzania and Ethiopia test for the disease, but the results are not that accurate.

So samples which come up negative are routinely sent to be double-checked by rats.

Carolina sniffed her way through 200,000 samples, identifying many positive cases.

But now she's retiring from her role with the global non-profit Apopo.

Harry Bly has the details.

This is the sound of sniffing, scuttling, and the soft squeaking of a giant African-pouched rat.

These rats at the Apopo Tuberculosis Detection Centre in Dara Salam in Tanzania can determine

whether a person has TB by sniffing a sample of their phleg, and it's all thanks to their

exceptional sense of smell. Humans do have up to 400 nerve endings in our nose and dogs do have

...