The chapter provides the comprehensive approach on the role of microorganisms in the biodegradation of plastics, including ambient bacteria (in vitro) and gut microbes of insects (in vivo). Microbial deterioration under ecological circumstances in vitro is prolonged for primary plastics at degradation rates depending on the various stages. However, recent discoveries indicate that the fast biodegradation of specific plastics, such as PS, PE, and PUR, in some invertebrates, mainly insects, could be enhanced at hourly rates; biodegradation in insects is likely to be gut microbial-dependent or synergetic bio reactions in animal digestive systems. Mechanical, photochemical, thermal, and metabolic methods can all be used to destroy plastics in the natural environment.