An estimated 700 million people visit zoos every year. Some people see these facilities as a great way to teach people about nature and to save species from extinction. Others think they’re cruel and unnecessary. It’s a heated debate. And now, as more and more people are watching animal rescue videos on Instagram and TikTok, it feels like the debate is hotter than ever.

William Lee Adams from the What in the Word team talks us through the history of zoos, including how England's Queen Charlotte (who was featured in Netflix’s Bridgerton) came to have twenty kangaroos, and how zoos have evolved. We also discuss their pro and cons. We hear from Tonya Lander, a biology lecturer at the University of Oxford in the UK, 19 year old animal rights activist Nikita Dhawan, and Delcianna Winders, Director of the Animal Law and Policy Institute at Vermont Law and Graduate School in the US.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 0330 12 33 22 6 Presenter: Hannah Gelbart Producers: Mora Morrison and Elena Angelides Video Journalist: Adam Chowdhury Editor: Verity Wilde

In November, fifteen people were killed at the Novi Sad railway station in Serbia when a concrete canopy collapsed. Students in the country have been protesting ever since, claiming that government corruption contributed to the tragedy. The protests have brought the country to a standstill, and on Monday students occupied the public TV station RTS. Slobodan Maričić from BBC Serbian tells us about the student protests, what he’s seen when out reporting and the criticism faced by President Aleksandar Vučić.

We also hear from several student protestors and Konstrakta, a popular singer. She explains why students have been so effective leading and organising the protests and how their movement has expanded to include people of all ages.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 0330 12 33 22 6 Presenter: Hannah Gelbart Producers: William Lee Adams, Emilia Jansson and Benita Barden Editor: Verity Wilde

Two weeks ago $1.5 billion vanished from a cryptocurrency platform - it’s thought to be the biggest crypto heist ever. They had fallen into the hands of some infamous hackers - the Lazarus Group. These hackers have alleged ties to the North Korean government and have managed to steal huge amounts of money from other crypto platforms before.

The BBC’s Cyber Correspondent, Joe Tidy, takes us through all the details and explains why North Korean hackers are so untouchable.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 0330 12 33 22 6 Presenter: Hannah Gelbart Producers: Emily Horler and Emilia Jansson Editor: Verity Wilde