What is biodiversity? Is it the animals, the plants, or their home together, meaning the entire nature? Is man part of biodiversity? Why was this word created? It didn't exist in the past. We constantly hear that we must protect biodiversity. Yet, our beloved dinosaurs disappeared, but life continued on the planet. Thanks to this extinction, our species found space to develop! Why save the species that are disappearing? And which ones should we save? Sure, the bears and seals, which we all love... But mosquitoes? Do they also deserve a place among us? Viruses? Those dreadful microorganisms that attacked us so badly recently, should they also be protected? A child, who knows very well the importance of the food chain and is bored of hearing the same things over and over, talks with his father. In their discussion, the dinosaur, the mosquito, the viruses, and many animals, plants, ecosystems, and the wonderful web of relationships that develop between them and with humans appear. In the background... the enormous threat posed to our planet by the loss of biodiversity and a precious relationship that we must take care of: the relationship between nature and our health.