Mice are not man’s best friend. The House mouse like our houses because mice are opportunistic, and because life in the wild is usually more perilous for them than life with us. Heavy predation, weather and starvation are all great threats to the house mouse, especially in the wild. Exponential reproduction rates and the short period between birth and sexual maturity more than make up for high mortality rates.
In reading the research about mice, writers usually refer to mouse life away from a human structure as the “wild” and mouse life in a human structure as “domestic” or “tame”. This somehow implies that they are welcome visitors to the human household. Unless you have some pet mice I think you would agree that they are not welcome. Sometimes cottagers will just resign themselves to coexist with the resident House mouse population rather than exhaust themselves trying to get rid of them. But “welcome” usually does not describe our feelings toward them. Rather than exhaust myself trying to reform all these writers who use the words “domestic”, “tame” and “wild” to describe these different habitats I have succumbed to the convention myself.
It is not hard to imagine that the House mouse, or Mus musculus,has many subspecies. Any species that can produce so many generations in a short time will evolve quickly in response to new environmental pressures. One such subspecies is an albino mouse that is sold in pet stores. Several species have long been used in labs, especially in medical labs and labs where genetics constitutes the prime focus of research. Because of their value in research the mouse’s genetic code was one of the first to be mapped.
An article in the Howard Hughes Medical Institute publication relates that in the 17th Century in Japan and China mice were raised as pets and bred for their beauty and unusual traits. The practice caught on in England where breed catalogues were created to the joy of mice fanciers. The fad moved on to North America where in 1900 a lady named Abbie Lathrop in Massachusetts bred mice on her farm. Later she began to sell one subspecies to Harvard University for research. This subspecies started the line that has become the standard mouse in research labs all across North America.
Territorialism in House mice is used to protect whole households rather than the territory of any individual mouse. It is enforced by both the male and the several female mates of his polygamous family. Each female usually visits the whole territory during the course of a twenty-four hour period. While mice are primarily nocturnal they may well search for food sources during the day if the night’s marauding was not particularly productive. Mice tend to rest and search in short cycles, competing as many as 15 cycles each day.