Hammocks
I’m of the firm belief that every rat should have a hammock, and to deprive them is some unforgivable form of torture:) For some inexplicable reason, rats adore them, and will all pile in no matter what other forms of luxury are offered. It's pointless to buy one, as rats will pull out all the stuffing in no time. Rats are nestbuilders as well as rodents, and that’s just what they do! I make my hammocks out of polar fleece, as this is the material that rats are least likely to chew on. A yard of fleece for $5 at Fabricland makes 6-9 hammocks to fit my cages, which I can change every other day. I fasten them to the bars with safety pins. Never use plastic diaper pins because once the rat chews the plastic, the pointed end will *thwang* loose and poke them in the face.
Roll-a-Nests - *LETHAL* WARNING
These come in various sizes, and are fine for just a couple of rats. However if they have only one entrance hole, a number of rats piling into them can cause the rats at the back to be trapped and suffocate to death. That does for any small dwelling with only one entrance.
Roll-a-Balls
It's in a rat's nature to explore, and they hate to be confined. They may panic in these, and/or become sick due to the stress.
Wheels
In addition to being exploratory creatures, their intelligence usually supercedes their need to exercise. Rats are much like humans, and will always pick the shortest route to a task (ie. mazes), resulting in them becoming lazy if permitted. What I'm trying to say is rats aren't much interested in doing all that exercise and getting nowhere. You can try introducing a wheel at a very young age, but don't be disappointed if they don't use it. it's *critical* to make sure the floor of the wheel is solid, so delicate rat limbs don't slip down between rungs and break. Other suitable wheels are metal with a grid-pattern floor. Personally I'm afraid of rats getting injured by getting a head caught between the wheel and the stand, or on one of the supporting arms.
Igloos
May be OK, depending on the rats. You can fit a small dish on top too. Some rats will constantly pee in them rather than climb over other rats to get out, which makes for a dangerous concentration of ammonia. My rotten boys are of this sort, and the shavings beneath were always soaked. I removed all igloos (and other dwellings a number of rats could gather underneath) a year ago because they were waking up with the sniffles and sneezes and I feared long term damage to their lungs. If you use these, you should check underneath twice a day for urine, changing the litter if there is a little urine, and discontinuing if it is soaked every day.
Baskets
I replaced the igloos with these small baskets picked up from the dollar stores. There's a potholder at the a bottom, which is changed daily.
Other items
I provide my rats with plastic pop bottles and fruit-scented wood chews (they dislike the unscented Hagen ones) in their cages to distract them from chewing plastic shelves, toys, and bars. I give them paper to satisfy their nest-building instinct, which is an alternative to shredding their hammocks and other fabric in the cage. They often drag the paper up into their hammocks—so cute! Rats are stashers, and enjoy a variety of treasures (buttons, bottle caps, marbles and other trinkets) to hide in their cage or at free range time. They can often be caught stealing from each other’s stashes, which keeps them busy.
