Organisms occupy a specific position in an ecosystem based on their source of food which is known as trophic levels. In trophic levels, the first level is occupied by producers second by herbivores and third level by carnivores. These levels do not depict the species but their functional level. A sparrow becomes a primary consumer when it eats seeds and secondary consumers when it feeds on worms. Hence a given specie can occupy more than one trophic level at the same time in the ecosystem. In the most ecosystem, the pyramid of energy and biomass is upright as producers more in number and biomass than herbivores and herbivores are more in number and biomass than carnivores.