What is the primary role of a bee's sting?

The primary role of a bee's sting is to defend the colony against predators. When a bee perceives a threat to its hive or its queen, it can use its sting as a means of protection. The sting injects venom, which can deter or incapacitate potential threats like larger animals or intruders. This defensive behavior is crucial for the survival of the colony, as it helps maintain the safety of the queen and the brood.

The other options relate to the various functions and contributions of bees, but they do not encapsulate the main purpose of a bee's sting. Collecting pollen and pollinating flowers are vital roles that bees perform for foraging and the ecosystem, but these actions do not involve the use of the sting. Cleaning the hive is another activity that promotes hygiene within the colony, yet it does not pertain to the use of the sting. Emphasizing the defense aspect highlights the critical relationship between bees and their protective behaviors within the colony structure.