What is one thing that would increase the carrying capacity of the rat ecosystem?

One factor that could increase the carrying capacity of the rat ecosystem is the availability of abundant food resources, such as grains or waste from human activity. Improved shelter options, like nesting sites or burrows, can also support larger populations by providing protection from predators and harsh environmental conditions. Additionally, reduced competition from other species or decreased predation can further enhance the ecosystem's capacity to sustain a larger rat population.