Make sure the bars aren't too wide, if they have babies they are tiny. My daughter bought two males (Joey and Chandler) and Joey turned out to be a girl and we found 6 babies in the house and about 6 weeks later we found another 5!!! When we took the lid off the cage two of them jumped out - they are very fast. Ended up we had to take them back to the shop - they were breeding like rabbits!!