Why do silkworms have a spike at the end?

Silkworms, specifically the larvae of the Bombyx mori moth, have a spike at the end of their bodies primarily as a defense mechanism. This spike can deter potential predators by making the silkworm appear less palatable or more difficult to eat. Additionally, it may play a role in helping the larvae anchor themselves in their environment as they prepare to pupate. Overall, the spike serves to enhance their survival during vulnerable stages of their life cycle.