What do antibodies attach to on the pathogen

Antigen

Explanation:

Antigens are present on the outside of the pathogen and trigger the immune system response to send out antibodies, which attach to these antigen 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.

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.