What are the pros and cons of keeping a mouse?

Pros :-
Mice are pretty much the smallest rodents kept as pets and are also among the least expensive. While a 10 gallon aquarium will hold a single hamster or a pair of gerbils, a small colony of mice can be kept in one, particularly if one goes to move than one level. Mice are also available in a very wide variety of colors and varieties, including satin, long haired, and curly haired mice. There is an active "mouse fancy" through which one may find these rare and beautiful varieties, meet with other mouse hobbyists, and show mice.

Cons :-
The two big negatives of mice are their reproductive capacity and their smell. A pair of mice, with sufficient care, can produce an amazing number of offspring. Since they mature quickly, a mouse owner can quickly become overwhelmed as the litters begin to have their own litters. While it is usually quite easy to get pet stores to take mice, they are usually taken for use in feeding reptiles and snakes. While a particularly owner may not have any quibble with the snake's eating habits, most mouse owners don't want their mice meeting with this fate.

The second problem with mice are the smell. While they are the smallest of all rodents, they are probably the smelliest. They will usually adopt a single area for their bathroom and you can change the litter here more often, but in general, these are not good pets to have if you do not have a spare room for your hobby.