Why is it important to define what a living thing is?

So people know that everything has a value and they should appreciate it.

Explanation:

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.

a. by using fur or clothes to trap heat energy near the body