Snake research. Male biologist locating an asp (Vipera aspis) with a radio antennae and receiver. This viper has a radio tracking device and thermal probe inside it. The probe allows the snake's body temperature to be measured remotely. Asps are poisonous European snakes 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.