Snake research. Male biologist measuring the body temperature of an asp (Vipera aspis) using a radio antenna and receiver. The antenna picks up signals from a combined thermal probe and radio tracking device that has been inserted into the snake. Asps are poisonous European vipers that live around the Mediterranean. The biologist is from the Centre d'Etudes Biologiques de Chize of the Centre Nati- onal de la Recherche Scientifique (CNRS), France.