Hello, got my first mouse as a single because she had a URI, thats all gone with antibiotics... "Cheddar" is about 8 weeks old.... i knew i need to get her friends so i have picked up 2 other mice from ( i know im bad) a feeder breeder... "Swiss" is about 3.5 weeks old and the other "Gouda" is only about 2.5 weeks old. He said i could take whatever i wanted as long as their eyes were open... im watching them intently to see if they are eating and drinking.. which they are and i'v offered kitten milk and bread. How should i go about introducing "Swiss" and "Gouda" to my other older mouse? ther is quite a size difference! Thanx for the advice!!