Tropidophiidae

Tropidophiidae is a family of non venomous snakes commonly called dwarf boas or thunder snakes, with two living genera and 34 recognized species. They range through the Neotropics from Mexico and the West Indies south to southeastern Brazil, with the greatest diversity in Cuba, where new species are still being found. These are small to medium snakes, typically 30 to 60 centimeters long, living a fossorial lifestyle, sometimes showing striking color patterns, and capable of changing color with activity level; when threatened they can bleed voluntarily from the eyes, mouth and nostrils as a defense. Two genera once placed in this family, Ungaliophis and Exiliboa, have since been reclassified as more closely related to the boas.