The Brown Rat or the common rat is a rodent from Europe. It is true omnivorous it eat anything. It has a longer life than mice, but they breed very quickly and have litters up to 7. They are preyed on by larger animals such as cats, dogs and so on. It originally originated in Europe had spread across the world thanks to humans. They are one that can out compete other life in there habitats due to lack of predators, but in time predators will start eating them out controlling the population. In Australia, sometimes rat population get out of control and start to swarm and eat everything in site. Brown rats can be captured and tamed to become pets or used as lab rats.