Having a pet rat means taking them out so they have time to free range play. They are social animals and love to come out and be with their humans. They also need exercise and one of the great ways to get them their exercise is to play games with them. Not all rats will like all of these games, some rats don't like to play at all and just want to sit with you, let your rat guide you to what they like to do.
Pea Fishing.Fill a shallow glass or other heavy flat bowl or container with about 2 inches of water and add some frozen peas. Place it near where the rats are playing and wait to see if they will stick their paws into the water to fish the peas out. Some rats will swim around in the water eating peas.
Go For A WalkI had a pet ferret harness that I put on one of my large hamsters and two of my rats. It's the kind that has a harness that goes around the body so they don't get choked or hurt if they pull on the leash. Get them used to wearing the harness and leash and take them for a walk. I got some really interesting looks when I did this.
Hide The TreatA toilet paper tube makes a great toy to stuff with raw vegetables and give to the rats. They will run around the cage with it until they can find a spot of tear it open. Just put the vegetables in the middle of the tube and fold in the ends.
Two of my boys are old now and they don't play much but they still like to come out and be held and just sit with us. Lucky, my younger one likes to play attack the hand, where he will chase my hand around until I tickle his back and then he turns around and play bites me, never really biting me. But trying to force my hand into submission.
If you have rats you already know that they have a lot of energy and need to do something during the day to expel that energy. So if you don't have time to spend with your rats during the day when they are awake and needing attention...don't adopt rats.