What fact supports the opinion that paper bags are less harmful than plastic bags

Paper bags can decompose in the environment in about a month meanwhile plastic can take hundreds of years. Plastic is harmful in many other ways too, for instance they release toxic chemicals into the earths soil and land and sea creatures can get caught in plastic or eat it and later die.

option number one would be youre best option

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.