Furnishing the cage part 2:
As I said before, rats need to be entertained. Hammocks and tunnels provide entertainment as well as places to sleep, but rats also need toys that provide entertainment as well as opportunities to chew! Rats teeth are always growing so they need lots of things to chew to wear them down!
For toys just take a trip to the pet store and head to the small animal section. There you will find tons of great toys for your rats like:
wood blocks and sticks
willow sticks and willow balls
sisal rope chews
hanging chew toys
All of the above toys are great for rats!
Another place to look for some great rat boredom busters is the bird section. Hanging bird toys, ladders, and rope toys are great for rats to chew and provide lots of climbing opportunities.
Note: when purchasing bird toys for rats avoid the ones with plastic and beads. Look for toys that only contain rope and wood.
You can even find great rat toys just laying around the house! Cardboard boxes are awesome for rats to play with (preferably ones without dye). Paper towel and toilet paper tubes are great too. Tip: Cut toilet paper and paper towel tubes in half or make one long cut along the tube lengthwise. Why? Rats trying to crawl through the tubes can get stuck!