Why does living in a pride in the survival of the species overall?

it increases the chances of female lions taking care of cubs along with male lions.
it increases the chances of lions surviving a natural catastrophe.
it increases the chances for sufficient food availability due to successful hunts.
it decreases the chances of diseases spreading among lions.

It increases the chances for sufficient food availability due to successful hunts.

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.