Despite the fact that they are often considered pests, mice have been utilized by humans in various ways throughout history. They have, for instance, served as food in some areas, as well as a source of fur. Also, in recent years, the active, playful animals have become fairly common as pets. Nevertheless, the single greatest use of mice occurs in the laboratory. Laboratory mice are special breeds of house mice, which are utilized in many scientific experiments because of their close mammalian relationship to humans. They are further well suited for such studies because they are easy to handle, inexpensive to house, and breed quickly. Information gained from work with laboratory mice has been invaluable to the modern understanding of anatomy, physiology, genetics, and behavioral science.