It depends on the type of animal, but if, for example, you're talking about one lower on the energy pyramid (like a chicken, for example) then this is because of the energy distribution. When an animal consumes something else, it absorbs about 10 percent of the energy of that creature.
So, lets say a plant has 1000 units of energy. Then a bug comes along, and eats the plant, absorbing 100 units (10 percent) of that energy. Then, a chicken eats the bug, absorbing only 10 units of that energy. Finally, a human eats the chicken, getting only 1 unit of the original energy.
The reason that something like a bug has to eat less than a human, is because it gets more energy directly from the plant.
Prolong feeling of sadness, loss of interests, angry outbursts, tiredness, sleep disturbances, anxiety, loss of appetite, slowed thinking, feeling of worthlessness, frequent/reoccurring of suicidal thoughts, unexplained physical problems and having a hard time thinking. [These are just a few symptoms]
Marks your distance in order to track calories lost
