Plastics are versatile materials with high mechanical and chemical resilience that are mostly made of long polymer chains. They are utilized extensively across a wide range of industries. A severe environmental issue is being caused by a number of conventional plastic polymers that are difficult to decompose and progressively build in the environment. To address this issue, innovative treatments or control technologies are urgently needed. While a variety of microorganisms break down plastic in various habitats, the pace of degradation is astonishingly sluggish; nonetheless, this process potentially speeds up inside an insect host. Plastics are often digested by these insects and then transformed into delicate fragmented forms by their collective chewing operations. By employing microbial enzymes, the gut microbes break down plastic polymers into more easily assimilated forms. Insect species vary widely dependent on plastic’ chemical composition, structure, and biodegradation processes. It is essential to explore for environmentally sound alternatives to conventional disposal techniques in order to get past the problem of plastic build-up. Regrettably, little is currently known about how plastics degrade and how well they do so. This chapter focuses on the different insect species that break down plastics, the types of polymers that these insect species break down, and the mechanism of degradation that occurs in the microbial environment of the insects’ guts, with a particular emphasis on the implications for sustainability.