Claus Meyer / Two-striped Forest Pit Viper (Bothrops bilineatus) coiled around plant, front view, Atlantic Forest ecosystem, Brazil

Claus Meyer / Two-striped Forest Pit Viper (Bothrops bilineatus) hanging on a Heliconia (Heliconia sp) flower, Atlantic Forest, Brazil

Lucas Bustamante / Green jararaca / Two striped forest pit viper (Bothriopsis bilineata) on branch, Tambopata, Madre de Dios, Peru.

Lucas Bustamante / Two striped forest pitviper (Bothriopsis bilineata) curled up on log, Yasuni National Park, Orellana, Ecuador.

Pete Oxford / Two-striped forest pitviper (Bothriopsis bilineata smaragdina) Amazon, Ecuador. Captive, occurs in the Amazon.

Pete Oxford / Two-striped forest pitviper (Bothriopsis bilineata smaragdina) Amazon, Ecuador. Captive, occurs in the Amazon.

MYN / Andrew Snyder / Bi-striped viper (Bothriopsis bilineata) Chenapau, Guyana. Meetyourneighbours.net project.

MYN / Andrew Snyder / Bi-striped viper (Bothriopsis bilineata) Chenapau, Guyana. Meetyourneighbours.net project.

Luiz Claudio Marigo / Jararaca snake {Bothrops jararaca} Brazil

Mark Moffett / Jararaca (Bothrops jararaca) coiled in vegetation, most common viper in the Atlantic Forest, Brazil

Michael & Patricia Fogden / Two-striped Forest Pit Viper (Bothrops bilineatus) coiled on rainforest floor using tip of tail as lure, an example of caudal luring, Amazon, Peru

Claus Meyer / Two-striped Forest Pit Viper (Bothrops bilineatus) coiled around plant, Atlantic Forest ecosystem, Brazil

Claus Meyer / Two-striped Forest Pit Viper (Bothrops bilineatus) coiled around grasses, Atlantic Forest ecosystem, Brazil

Mark Moffett / Jararaca (Bothrops jararaca) climbing tree trunk, most common viper in the Atlantic Forest, Brazil

Joel Sartore / Photo Ark / Jararaca (Bothrops jararaca) coiled up, portrait, Kentucky Reptile Zoo. Captive, occurs in South America.

Joel Sartore / Photo Ark / Jararaca (Bothrops jararaca) with head raised, portrait, Kentucky Reptile Zoo. Captive, occurs in South America.

Fernando Faciole / Jararaca pit viper (Bothrops jararaca), highly venomous, slithering over forest floor. Serra da Bocaina National Park, Rio de Janeiro, Brazil.

Lucas Bustamante / Two-striped forest-pitviper (Bothrops bilineatus) resting on leaf at night, Yasuni National Park, Orellana, Ecuador.

Daniel Heuclin / Two-striped forest pit viper (Bothrops bilineatus bilineatus) on a branch, from Venezuela to Brazil. Captive.

Daniel Heuclin / Two-striped forest pit viper (Bothrops bilineatus bilineatus) on a branch, from Venezuela to Brazil. Captive.