What is a rat's biggest enemy?

A rat's biggest enemy depends on whether it is a wild rat living outdoors, a city rat, or a rat inside a home, but overall its most dangerous enemies are natural predators and humans. In the wild and in rural areas, the biggest natural predators are birds of prey like owls, hawks, and eagles, which hunt rats at night and during the day with keen eyesight. Other major predators include cats, dogs, foxes, coyotes, snakes, and weasels, all of which are skilled rat hunters. In urban environments, humans are arguably a rat's biggest enemy because humans set traps, use poison, seal buildings, remove food sources, and employ professional pest control to eliminate rat populations, and human activity destroys rat habitats. Domestic cats are also significant enemies in homes and neighborhoods, as their scent alone deters rats and they will kill rats they catch. For pet rats, disease and poor husbandry are bigger threats than predators. From a survival perspective, a rat's biggest enemy is exposure, lack of cover, and lack of food, because without shelter and food they cannot survive. So in nature owls and cats are top predators, but in human environments, humans and human methods are the most effective enemies that control rat populations through exclusion, sanitation, and trapping.