Why do some plants have thorns?

Many plants have thorns as a defense mechanism to protect themselves from herbivores that might otherwise eat them. Thorns are modified branches, stems, or leaves that make it difficult for animals to graze on the plants. Some plants, like cacti, have spines to reduce water loss and provide protection. Thorns can also act as a deterrent for animals that might damage the plant while trying to reach the plant’s nutrients or seeds. This adaptation helps plants survive and reproduce in competitive environments.