The film presents the tropical tree-frog, two-color phyllomedusa, the "monkey-frog" of Amazonia. By day, it lives perched on top of the trees and gets down at night to refresh and feed. Its interest for the scientist is double: on the one hand, its skin contains impressing quantities of molecules that are biologically active and therefore easy to extract; on the other hand, these molecules can most of the time be found in the brain and intestines of mammals. For the first time, phyllomedusa have been bred and scientists of the Jacques Monod Institute can study the characteristics of these molecules. This research has already led to the discovery of new molecules that can be used in pharmacology ( for instance with antibacterial or analgesic capacities ).