Each level of the energy pyramid is smaller than the level directly below it because energy is lost as it flows from one trophic level to another. This loss of energy occurs due to various factors such as metabolic processes of organisms, heat production, and energy loss in the form of waste and non-digested food. Only a fraction of the energy stored in the biomass of one trophic level is passed on and available to the next level. Therefore, the amount of energy available at each higher trophic level decreases, resulting in a smaller biomass and thus a smaller population of organisms at each level.
