At the colony level, the pollen and sugar are the resources used to produce the machinery--combs and new workers--that will in turn use similar resources to produce drones and new queens, the factory's product."" Thus Heinrich (Entomology, Berkeley) considers the bumblebee in terms of energy economics. The book, which grew from a 1976 sabbatical study at Harvard's Museum of Comparative Zoology--Edward O. Wilson's bailiwick--details how the bumblebee's behavioral and physiological means of thermoregulation, which is necessary for flight and incubation, optimize energy returns per units of time and energy spent in foraging for the sugar/fuel--and how bees and flowers have coevolved according to the bees' goal of reaping maximum rewards and the flowers' of supplying the least amount of food necessary to attract pollinators. Heinrich's terminology conforms to his theme, as he calculates commuting costs and benefits and food-to-baby conversion ratios; explores foraging strategy in terms of individual initiative and competition; and compares the bees' physiological system to that of an internal combustion engine (specifically, the Lincoln Continental) and hive economy to a cottage industry system in the Adam Smith mode. (The honeybee colony, in contrast, is more like a big corporation.) Though critics of the sociobiology approach might well find such analogies unfruitful, it is impossible not to be impressed with the imagination and rigor with which Heinrich applies his considerable knowledge of the bumblebee to his energy-economics framework.