4 A female rat can mate as many as 500 times with various males during a six-hour period of receptivity—a state she experiences about 15 times per year. Thus a pair of brown rats can produce as many as 2,000 descendants in a year if left to breed unchecked. (A rat matures sexually at age three to four months.)Dec 7, 2006
Rats are often associated with filth and disease. So, if someone calls you a rat, it's not like being called a fox. ... These negative traits have led to the informal meaning of rat, "hateful person," "liar," or "double-crosser." You can also use rat as a verb to mean "betray or snitch on."
Adult mice, on the other hand, will have adult proportions: a small, triangular head with a small nose and little delicate feet as compared to the body. In addition, mouse ears are very large relative to their heads, rat ears are smaller relative to their heads. Rats also have thicker tails than mice.