Sadly, often the only resource for pet mice are pet stores. I hate seeing any animal sold through a pet store as there is NO screening done on the homes. All the store has to do is verify tha the buyer is over 18 (a sale is a legal contract and in most areas – or at least the US, you cannot make a contract with anyoneunder 18). However, that said, your best bet is to contact a rat and mouse club (they do exist). http://www.rmca.org/ the above link has regional clubs in various areas of the US and even Ontario Canada. Check out your local rescue society regularly. It is amazing what gets turned into them. I have gotten many small animals from shelters and rescue groups as pets. If you are in another country, go to http://www.yahoo.com and type in the country and mouse clubs for a search of your area.