Why all of the energy that grass gets from sunlight passed on to trhe prairie dogs eat grass?

That's not quite right! Only a small portion of the energy from sunlight that grass gets is passed on to the prairie dogs that eat it. Here's why:

* Energy Loss in Photosynthesis: When grass uses sunlight to make food through photosynthesis, it doesn't convert all the sunlight energy into usable food. Some energy is lost as heat.

* Energy Used by the Grass: The grass needs energy to grow, maintain itself, and reproduce. This energy isn't available to the prairie dogs.

* The Ten Percent Rule: A general rule of thumb is that only about 10% of the energy from one trophic level (like grass) is passed on to the next trophic level (like prairie dogs). The rest is lost as heat, used for bodily functions, or not consumed.

In summary: Prairie dogs only get a small fraction of the energy that the grass initially captured from the sun. This is a fundamental principle of energy flow in ecosystems.