Insect cyborgs have been proposed for application in future rescue operations, environmental monitoring, and hazardous area surveys. An energy harvester for insect carrying is critical to the long-lasting life of insect cyborgs, and designing an energy harvester with superior energy output within the load capacity of tiny flying insects is very important. In this study, we measured the thorax vibration frequency of bees during loaded flight conditions. We propose a piezoelectric vibration energy harvester for bees that has a mass of only 46 mg and can achieve maximum effective output voltage and energy density of 5.66 V and 1.27 mW/cm