mantises are insects that primarily live on land and are known for their predatory behavior, while mantis shrimp are marine crustaceans with powerful claws and complex vision. Despite their similar names, they belong to entirely different animal groups and have distinct lifestyles and characteristics.mantises are insects that primarily live on land and are known for their predatory behavior, while mantis shrimp are marine crustaceans with powerful claws and complex vision. Despite their similar names, they belong to entirely different animal groups and have distinct lifestyles and characteristics.