The male praying mantis cannot copulate while its head is attached to its body. The female initiates sex by ripping the males head off.
Image from Wikimedia public domain.
Praying Mantis (Hover)
Praying mantises hunt down birds worldwide. Praying mantises are carnivorous insects with powerful raptorial front legs that usually depend on arthropods such as insects or spiders as their primary prey. Now new research indicates that praying mantises all over the globe include birds in their diet. Source 9q.