Anyone who has ever had pets or visited a zoo knows that mammals have a strong odor, and that this odor is species-specific. Even a microsmatic species like humans can easily distinguish the smell of a goat from that of a cow, a pig, a fox, and so on. There is an inverse correlation between the acuity of the sense of smell and the odor of the animal itself. Some of the most strongly smelling animals belong to the families Mephitidae (skunks) and Viverridae (civets). Rats and mice also have a strong odor.