Insecticide, any toxic substance that is used to kill insects. Such substances are used primarily to control pests that infest cultivated plants or to eliminate disease-carrying insects in specific areas. But most especially, insecticides are used mainly to kill bugs, flies, and so on, in the house or house environment. Insecticides are a form of pesticide; other pesticides include herbicides (weed killers) and fungicides (fungus killers).        POISONOUS INGREDIENTS CONTAINED IN INSECTICIDES Insecticides contain chemicals that are dangerous when misapplied, spilled or disposed of improperly. Some of these chemicals include: • Organochlorides • Pyrethrins • Carbamates • Ryanoids • Boric acid • Organophosphates • Nicotine • Paradichlorobenzenes (mothballs) • Formanidines • Organotins • Spinosyns • Pyrazoles • Pyridazinones • Quinazolines, and so on. Most of these chemicals are generally not harmful, but can cause life-threatening breathing problems if breat...