The answer to 'types of rat' is there are several common types of rats that can infest homes and businesses. The most prevalent are the Norway rat and the roof rat, also known as the black rat.
Norway rats are the larger of the two, typically weighing 12-16 ounces and measuring 13-18 inches long including the tail. They have stocky bodies, small ears, and blunt snouts. Roof rats are smaller, usually 5-10 ounces and 12-15 inches long, with slender bodies, large ears, and pointed snouts. Roof rats are excellent climbers and often nest in attics, while Norway rats prefer to burrow underground.