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Monarchs face many threats and stressors that result in declining populations in both the eastern and western regions of their North American range. The most significant impacts come from the loss of habitat for breeding, migrating, and overwintering. In addition, indiscriminate use of chemicals to control insects and weeds can have harmful unintended consequences for monarchs; a changing climate is making some habitat less suitable and forcing changes in migratory patterns; and monarchs face many risks from natural enemies such as predators, parasitoids, and diseases.