Constrictive snakes are a type of snake that are known for their ability to constrict their prey. Boas are a type of constrictive snake, and they are found in tropical and subtropical regions of the Americas, Africa, and Asia. Boas are non-venomous and typically hunt by constricting their prey until it suffocates. They can grow to be quite large, with some species reaching lengths of up to 13 feet.