The following points were adapted from Agdex 683 Revised October 1996 and other sources.  They are provided because so many people tell us that while they hate rats, they don't mind mice, because they are harmless.  Sorry to disappoint you - read this !

In six months, one pair of mice can eat more than 2 Kg of food and leave 18,000 droppings.  Food contaminated by mice is about ten times greater than what is eaten.

Mice are very destructive to rigid foam, fibreglass batt and other types of insulation in walls and attics.

Electrical wiring gnawed by mice causes many fires each year, listed a "cause unknown".

Mice and their parasites are implicated in the transmission of a number of diseases, including salmonella poisoning, rickets, and the potentially fatal hantavirus (Weils disease)
Most people associate Weil's disease with rats, but it is important to note that mice are also a cause of this distressing and potenially fatal disease.

Mice bear a litter of 5 or 6 young after a 21 day gestation period.  The female is ready to mate again 2 days later. The young are weaned after 21 days.  A single pair of mice can theoretically give rise to a population of 32,000 mice in a year, if all offspring survived to breed within the colony.

The house mouse will normally travel within an area of 10 ft. to 30 ft. to find food.  They will sample new foods readily. 

Mice are happy to live alongside cats and dogs (Tom and Jerry is only a cartoon - not real life), and while cats will sometimes catch mice, it is estimated that 95% of mice will avoid being caught.