Pit vipers. Pit vipers are a subfamily (Crotalinae) of vipers. There are about 190 species, according to ITIS. Pit vipers are found throughout the Americas, Europe and Asia.

news Environment. Eyelash pit viper boom: Dallas Zoo welcomes 6 to its scaly family Eyelash vipers hatch at Dallas Zoo for the first time in a decade. Here’s how and when to see them.