Shelters are great places to find mice that need homes.
is a fabulous site, and I recommend you study it, and post on the message board before aquiring a pet & while you have a mouse.
There is a rescue board there as well, you might want to check it out & see if there are any posters trying to find homes for their mice in your area.
Some quick tips you need to know before buying a mouse:
1. Boy mice live a lone. Sometimes, but very rarely, they can live with brothers or fathers. This only works if they live together from birth, but even then it doesn't work. Like you saw in the pet store. Boy mice, if not compatible, will fight to the death and need to be seperated immediatly. However, boy mice live alone very well. They are supposed to be much more friendly & outgoing than female mice. I only have females (getting a rescue boy next week). So I can't compare. My girl mice are friendly though, so if I get a boy that is even more friendly it will be great.
2. Girl mice need friends. Exaclty opposite of a boy mouse. Girl mice are social and need to have female company. It is also possible to put neutered male mice in with them, but because neutering isn't very common, getting another girl mouse or more is recommended.
3. Never use Pine/Cedar bedding for your mice. This bedding causes respitory infections which can kill mice. Recommended bedding is, carefresh (recycled news paper), Aspen, Corn Cob, and there are others listed on the RMCA site. Newspaper ink is also a debated bedding. Many mouse enthusiasts use inkless newspaper. You can buy the rolls of this from print shops. It usually is very cheap or free.
I use newspaper in my cages to line the bottom of the wood part, but rarely as actually bedding. However Mittens does rip it off sometimes for bedding.
4. Aquarium homes are not recommended because of the lack of air flow. Cages are the best (ones with narrow gaps between the bars). However I use an aquarium on the bottom of my cage, and they go down there to sleep because its quiet. You might also need an aquarium if you get a smaller mouse. My mouse Stina could escape the bars on an old bird cage when I first got her. I could barely put my fingers through the bars.
Baby mice would need to live in an aquarium at first.
5. Recommended food is the Nutriblock food. They are a more balanced food than the seed mixutres. Sunflower seeds are a great treat, but can be very fattening. The seed mixtures usually contain a lot of them.
6. Mice are wonderful pets! I assume you have kitties (because this is a cat board
). So you will have to take extra extra extra precautions before bringing a mouse into your home. But I know it can be done (as I currently have 2 mice and a cat).
Sorry this post is so long, those are the bare minimum basics to buying a mouse, RMCA has very knowledgable posters & information. I hope you can visit the site before buying a mouse!
I post on the boards there as Ducky as well, so feel free to ask me any questions if you need to.
I do not recommend buying a pregnant mouse as your first mouse. Pregnant mothers & babies require a lot of extra knowledge, money, time & space to care for. Something that could be overwelming for a new mouse mom or dad.