While there is a myriad of deodorants, shower gels and perfumes helping us stay fresh and fragrant today, that hasn’t always been the case. How did humans stay clean in the past, or did they not care so much? And is there an evolutionary reason for human body odour in the first place? These are questions that CrowdScience listener Sarah has pondered on trips in her camper van, when she wants to keep clean, but washing isn’t always convenient. In search of answers, presenter Anand Jagatia delves into the sweaty details: where body odour comes from, why some people's armpits don't smell, and whether this heady stink serves any purpose. Could our natural odour really help to attract a partner, or is it just a smelly bacterial by-product? Anand explores the intriguing mystery of human pheromones, and hears how for hundreds of years, Europeans were terrified of washing. Contributors: Dr Madalyn Nguyen, Dermatologist Dr Kara Hoover, Biological Anthropologist, University of Alaska Fairbanks Katherine Ashenburg, author, The Dirt on Clean: An Unsanitized History Dr Tristram Wyatt, Department of Biology, University of Oxford Presenter: Anand Jagatia Producer: Sophie Eastaugh Production co-ordinator: Ishmael Soriano Editor: Cathy Edwards Sound engineer: Emma Harth (Photo: Girl sweating smelly armpit, Taiwan Credit: PonyWang via Getty Images)