There are multiple factors that determine whether a worker bee will become reproductively active. A laying worker bee exclusively produces totally unfertilized eggs, which develop into drones. Therefore, the probability of personal reproduction by a worker bee is exceedingly low. Which subcaste a worker bee belongs to depends on its age. In the "Bombus morio," the average worker bee lives about 41.3 days. A female egg can become either a queen or a worker bee. A beehive cannot survive with only a laying worker bee. In July 2015, Elbow released the "Lost Worker Bee" EP. The worker bee is a symbol of Manchester, England. The worker bee is one of the best-known symbols of Manchester. A worker bee vibrates its body dorsoventrally while holding another bee with its front legs. If the cells are not clean, the worker bee must do it again and again.