First, various plants grow big and healthy from energy from the sun. These organisms are called Producers. They are also considered to be on the 1st trophic level.

YUM!

Once the plants are developed, the little grasshoppers happily hop over to them and treats themselves to a little snack. The grasshoppers are considered Consumers. They are also considered to be on the 2nd trophic level

YUM!

After the grasshoppers finish eating the plants...they receive only 10% of the energy that the flower had.

But soon after that, a VERY hungry chicken came by and saw the grasshopper...

The chicken is considered a Secondary consumer. He is also considered to be on the third trophic level.

The chicken finishes the grasshopper, and revives 10% of energy that the grasshopper had.

Up behind the bushes creeps a lion that hasn't eaten in a while...