Why not use chemicals? Pests are bad anyway.
Chemicals can kill pests and insects, so is it difficult to imagine that they could be harmful to us humans as well? This is the whole point behind our motto of "Be Organic". Let us understand that we (all insects, plants, animals and humans) are all part of Nature. What hurts one cannot help another. So, when you spray harmful chemicals to keep away mosquitoes or rodents in your house, remember that we would be inhaling or ingesting them as well, albeit in smaller quantities. For some of us, it may not cause any adverse reactions, but for most of us, it will show up somewhere someday. Small exposure to these harmful chemicals on a daily or regular basis could have long-term adverse effects on our health. Either as headaches or skin rashes at the milder level, or cancer or psoriasis on the extreme level. Unfortunately, most of us do not relate our diseases to our own actions. When we are sick, we tend to rush to a doctor, and are happy to ingest more chemicals in the form of pills or lotions or syrups!
Chemicals not only hurt the pests that they are intended to kill. They also cause "collateral damage" in other insects not harmful to our crops - earthworms and microbes in the soil, etc. leading to the collapse of the entire ecosystem that generates our food. Bees and other pollinating insects are among the worst impacted. The food generated out of this chemical treatment is less nutritious, less tasty and more harmful to humans.
A historical view of how chemicals came into food would be useful here. Right after the World War II, in the 1950s, the factories that were producing the poisonous chemicals for the war (nerve gas used during the Holocaust) lost the entire market for their chemical products. This is when it was found that some of these chemicals can artificially enhance growth in food crops. This is when these chemicals started being used in agriculture. Over time, many governments promoted this chemical agriculture (what we at Bio Basics call "Chemiculture"). In India, we went through the "Green Revolution" in the 1960s as we were temporarily short of food. The negative effects of this chemiculture on human health was not realized until later. Now after long battles led by many NGOs and civil society groups, both in courts of law and on the streets, many governments have banned the use of many of these chemicals (e.g. DDT, endosulphan, etc.) in farming. But in India, many of these chemicals, although banned in many countries, are still in use