Crotalinae, commonly known as pit vipers, are a subfamily of venomous snakes found primarily in the Americas and parts of Asia. They are characterized by their distinctive heat-sensing pits located between the eyes and nostrils, which help them detect warm-blooded prey. This subfamily includes well-known species such as the rattlesnake, copperhead, and fer-de-lance. Pit vipers possess a range of adaptations that aid in their survival, including a potent venom used for subduing prey. Their coloration often provides effective camouflage in their natural habitats, which can include forests, deserts, and grasslands. Crotalinae play a crucial role in their ecosystems by controlling rodent populations and serving as prey for larger predators