What is the life span of the praying mantis? Nick December 10, 2020 00:04 Updated Praying mantises live outdoors for 3-6 months. Related articles Are praying mantises predators? Do praying mantises fly? How can I tell whether a praying mantis is male or female? Fun Facts about the Praying Mantis Praying Mantis hatching tips and tricks Comments 0 comments Please sign in to leave a comment.