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 Producer: Imaan Moin, with Debbie Kilbride, Alice Lipscombe-Southwell, Noa Dowling, Harrison Lewis and Sophie Ormiston. Studio Manager: Cath McGhee