South America | Boa constrictors sense heat through the cells in their lips. These cells help the boa “see” infrared light. Even though these large snakes have two lungs, only one (the much larger right lung) is functional. Many snakes of the same family have actually evolved to not have a smaller non-functional lung and instead stick to having the one. . . . . . . . #animalsofinstagram #animalplanet #animaloftheday #wild #wildlife #outdoors #animals #wildanimals #conservation #nature #animallovers #instanature #wildgeography #wildlifeonearth #southamerica #boa #boaconstrictor