When a caterpillar eats a leaf, then a thrush eats the caterpillar, or when a hawk eats the thrush only 5 to 20% of usable energy is transferred from one level to the next. . . . Thus herbivores will account for a much smaller fraction of the biomass [than plants] and the carnivores for a still smaller fraction.
I love living on that stage. Without that, Id die.