Pesticides are used in agriculture, food production, and human habitations (Hsaio). Pesticides are substances used to repel, kill, or control animals or pests (Hsaio). They are categorized into two categories: synthetic and biochemical (Hsaio). There are various types of pesticides including chemical, bio, microbial, biochemical, and plant incorporated (Hsaio). The toxicity of pesticides can range from low to high, depending on active ingredients (NPIC). Bio pesticides are organic and synthetic pesticides are manmade (NPIC). Herbicides are substances used to control unwanted plants (NPIC). There are hundreds of herbicides, which are either selective or non-selective (NPIC). Selective herbicides only kill certain plants, non-selective herbicides kill all plants (NPIC). Some pesticides kill targets quickly, others can take over a week (NCIP). Some stay in the soil temporarily, others remain for a long time (NCIP).