Give them the largest cage you can house/afford such as a Chinchilla or Chipmunk cage.They are very active and they can swim, climb, run up exterior walls oh year and jump 3 feet.
They need a good rat food like Reggie Rat (supreme pet foods) and will eat meat, fruit, veg annd dairy products but offer in moderation. As a treat boil an egg and wait till it cools. Then cut it in half and give it to the rat. They love them.
Go for shavings and dont use sawdust or hay as it will irritate their eyes. You can give them parrot toys or rodent toys or you can make your own. Ropes, ladders, boxes etc.
Keep the cage out of draughts and full sun.
You never pick rats up by the tail as this is very sensitive and can be very painfull. You lift them by gently grasping their abdomen with one hand and support their weight with the other. If you do need to restrain one gently but firmly hold the base of its tail right next to the body.
Hamster bedding is ideal for nesting material which they will cuddle up in. If you have a fair bit of time one rat will be fine. If you haven't then get the rat a friend to prevent him from becoming lonely.
They are very inteligent so create things for them to do. Dont offer treats straight to them. Hide them in the cage or inside a toy or box, keeps their minds occupied.
Have fun
