Cute Rat

Brown rats are often used as model organisms for scientific research. Since the publication of the Rat Genome Sequence, and other advances such as the creation of a rat SNP chip, and the production of knockout rats, the laboratory rat has become a useful genetic tool, although not as popular as mice. When it comes to conducting tests related to intelligence, learning, and drug abuse, rats are a popular choice due to their high intelligence, ingenuity, aggressiveness, and adaptability. Their psychology, in many ways, seems to be similar to humans. Entirely new breeds or "lines" of brown rats like the Wistar rat have been bred for use in laboratories. Much of the genome of Rattus norvegicus has been sequenced.
As food
Rat meat is a food that, while taboo or even forbidden in some cultures, is a dietary staple in others. Taboos include fears of disease or religious prohibition, but in many places the high number of rats has led to their incorporation into the local diet.