Michael & Patricia Fogden / Eyelash Viper (Bothriechis schlegelii) showing loreal pits for detecting heat, rainforest, Costa Rica

Pete Oxford / Bushmaster (Lachesis muta), native to South America

Vincent Grafhorst / Malagasy Boa (Sanzinia madagascariensis), Marozevo, Madagascar

James Christensen / Ringed Tree Boa (Corallus annulatus) showing prominent loreal pits for heat sensory, Colon, Panama

Michael & Patricia Fogden / Eyelash Viper (Bothriechis schlegelii) close-up portrait, Costa Rica