In a mushroom, what is the visible umbrella-shaped portion known

The umbrella-like structure in a mushroom is called the fruiting body. The fruiting body or the pileus is the cap of the mushroom that produces spore in order to reproduce. They vary in different sizes and are classified according to their structures.

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.