Crotalidae refers to a family of venomous snakes commonly known as pit vipers or rattlesnakes. These snakes are typically characterized by their triangular heads, heat-sensing pits located between their eyes and nostrils, and rattling tails. Some synonyms for Crotalidae include Viperidae, which is a broader family that includes all venomous vipers, and Crotalus, which is a genus specific to rattlesnakes. Other synonyms for Crotalidae may include pit vipers, crotalines, or venomous snakes with heat-sensing pits. It is important to note that while these snakes may have different names, they are all highly venomous and should be treated with caution.