Exotic species are plants or animals that are introduced to a new environment where they do not naturally occur. These species can arrive through various means, such as travel, trade, or accidental transport. While some exotic species can adapt well and coexist with local wildlife, others may disrupt the existing ecosystem. When an exotic species becomes invasive, it can outcompete native species for resources like food and habitat. This can lead to a decline in biodiversity and negatively impact the ecosystem. Examples of invasive exotic species include zebra mussels and kudzu, which can cause significant ecological and economic harm.