Why should pesticides be used judiciously?

Why should pesticides be used judiciously?
Answer:
Pesticides are the chemicals that are used to control weeds, insects, rodents, fungi as well as diseases of plants. Their excessive use causes environmental pollution. They reach the water resources and affect the aquatic flora and fauna. These harmful chemicals reach the bodies of birds, animals and human beings through various food chains and are thus, harmful to all depending on their concentration in the body.