They are both about a year and a half old. Ulysses is 3 days older than Jay-Z, and Jay-Z is the runt (although he doesn't act like it) so Uly is bigger. They are smart little guys- they figured out that if they knock their water bottle off the cage I will come over to put it back, and talk to them, so they have me trained. Actually, Jay-Z only knocks off his water bottle when he's out of water, and it works. I always get him more water and apologize profusely. I talk to Uly in the morning every day as I'm leaving, and in the evening when I come home. Jay-Z is usually asleep. He wakes up when I come over with nuts, carrots, or popcorn. They are spoiled. They get treats every night. They are totally worth it! I am crazy about them. I even mail order their special rat food, Regal Rat. It is the best. It looks like dry cat food, but its much better than the food they sell at the pet store because they only eat it when they're hungry (instead of frantically eating everything I give them immediately). I don't know why. They lost weight when I started giving them the Regal Rat. Pet rats, especially males, have a tendency towards obesity. Too bad they don't run on their wheel anymore. Maybe I should give them more baths- I tried to wash them in the bathroom sink a while ago, and they could not get away from me fast enough! Even Jay-Z was running all over the bathroom floor while I tried to dry him off with a little towel. They forgave me, after I gave them treats. Treats smooth over any people-rat friction. Too bad that doesn't work for everything. I love my rats! They seem to like me okay, too. Ulysses hangs on my every word, and Jay-Z puts up with me, which I appreciate. They are the best little rat guys a girl could have.