In the terrestrial food web above, what would be the effect of a farmer introducing a rat poison in to the ecosystem that is toxic to rats and mice?

As explained below

Explanation:

The terrestrial food web is a food web that is characterized by all land animals and is largest terrestrial food chain on earth as the farmer tends to introduce a rat poison in this food web the rat may get killed by the medicine but if the same rate may be eaten by a snake the poison that killed the rat may infect the snake. Hence the pollutant may climb up the ladder and intoxicate the hawk that depends on small animal for prey which may be further eaten by a man or other animal like a cat may then spread this disease or the infection to other upwards in the food chain and thus the process of Biomagnification takes place in the ecosystem.

Photosynthesis. . .