Infester is a word that depicts the action of pests or unwanted organisms multiplying rapidly in a particular area. However, there are several alternative terms that can be used to convey the same meaning. Some of these synonyms include overrun, invade, infiltrate, swarm, infest, plague, and overtake. These synonyms can be applied in different contexts, depending on the type of organism that is causing the infestation. For example, "overrun" can describe an area that has been taken over by rodents, while "infiltrate" can describe the invasion of termites deep within the wooden structures of a building. Ultimately, the use of synonyms for "infester" allows for a wider range of vocabulary and better communication of an infestation problem.