Functional Compensation in a Honey bee’s Damaged Tongue while Dipping Nectar

A honey bee has to visit 3000 flowers to produce one-gram of honey. A honey bee’s hairy tongue dips at an average frequency of 5 Hz, and its glossal hairs erect rhythmically, performing like an opening and closing umbrella to trap the nectar. Dipping by a honey bee tongue is a typical micro-fluidic transport with a low Reynolds number. The high intensify of feeding activities inevitably damage on the fragile tongue structure. We found that that in nature, honey bees with incomplete tongue tips can still load the nectar with hairs erected. Furthermore, the hairs deploy more to form a larger umbrella-like configuration, and the dipping frequency augments when tongues are damaged on the tips, possibly compensating for the nectar intake loss caused by structural damage. Here we examine by experiments and modeling the functional compensation facilitated by the compliant mechanisms in the honey bee tongue. We put forward a fluidic transport model to evaluate nectar intake rate in a damaged tongue, considering variation in hair erection angle and dipping frequency. Theoretical analysis indicates that both mechanisms compensate for nectar intake loss caused by damaged tongue. The findings suggest a new mechanism for functional compensation in flower-visiting insects that may prove useful in engineering applications.