Housing

Space Requirements

Rats need a lot more room than most people expect. The general guideline is about 2 cubic feet of space per rat, but the amount of floor space is just as important. As a baseline, plan for at least 2 square feet of floor space per rat. Tall cages with multiple levels are great because rats love to climb, but height should be in addition to, not instead of, a roomy base.

A cage that’s 30 inches long and 18 inches wide, for example, gives 3.75 square feet of floor space. That’s fine for two rats, but if you add a third it starts to feel crowded. Once you get into groups of four or more, you really want something much larger, ideally a double-unit cage. The takeaway is simple: when you’re choosing a cage, always think about the footprint first, and then the height.

Space Requirements Guide

Number of RatsMinimum Floor Space (sq ft)Minimum Total Space (cubic ft)Notes

2 rats4 sq ft4–6 cubic ftAbsolute minimum for a pair. Bigger is better.

3 rats6 sq ft6–8 cubic ftWorks for a trio, but more floor space helps.

4 rats8 sq ft8–10 cubic ftAt this point, a double-unit cage is best.

5–6 rats10+ sq ft12+ cubic ftLarge, tall cages strongly recommended.

7+ rats14+ sq ft16+ cubic ftGo as big as you can. Group needs space to avoid stress.

💡 Note: These numbers are minimums. Rats will always benefit from extra space, so aim higher if you can. A bigger cage not only makes them happier, it also spreads out the mess so you spend less time cleaning.

Tanks and Enclosures

Glass tanks, aquariums, and other enclosed setups do not work for rats, even if the math looks right on paper. The problem is airflow. Tanks trap heat and ammonia, both of which build up fast in a small space and can irritate the rats’ lungs. They also don’t offer much climbing room. Rats will use the full height of a tall wire cage, but a glass tank limits them to just the floor. Even if it technically meets the size minimums, it will never be as healthy or stimulating as a proper cage with ventilation.

Group Size

Rats are social animals and should never be housed alone. Two is the bare minimum, but three or more is much better. In pairs, one rat may sometimes end up lonely if the other gets sick or passes away. With three or more, there’s always companionship and the social balance feels more natural. Planning for at least a trio also saves you the stress of having to suddenly add a new rat later if one dies unexpectedly. If you think you only want two, it’s worth sizing up in advance — most people end up adding a third sooner than they thought.

Cage Height

Floor space is critical, but rats also love to climb. A cage should be at least 24 inches tall, though taller is always better. Rats will use every shelf, hammock, rope, and bar you give them. Multi-level cages are perfect because they create more usable space without making the footprint too huge. Just make sure there are safe ways to move between levels — ramps or shelves that are close enough together so falls aren’t dangerous. A tall cage that’s empty in the middle isn’t useful, but a tall cage with smart levels gives them exercise and keeps them busy.

Placement in the Home

Where you set up the cage matters almost as much as the cage itself. Rats do best in an area with good airflow but not directly in a draft. Avoid putting the cage near windows where sunlight heats it up, or next to heaters, AC units, or vents where the temperature swings too much. Keep them out of kitchens, garages, or damp basements, since fumes and humidity can be harmful. The best place is usually a living room or bedroom where people spend time. Rats enjoy being around household activity, and being near you also makes them tamer and more social.

Clutter and Cage Setup

A cage is only as good as how it’s set up. A bare cage, even a large one, feels empty and boring to a rat. Adding hammocks, hideouts, ropes, ladders, and toys makes the same space feel much larger. Clutter gives rats places to explore, nest, and play. In fact, a well-furnished cage can comfortably house more rats than the same size cage with nothing in it.

That said, there’s a balance. If you overpack the cage, they won’t have room to run or wrestle. Think of it as zoning: leave open areas for movement, cozy spots for sleeping, and climbing routes that link everything together. When the cage is set up this way, your rats will make full use of the space and you’ll get to see a much wider range of their natural behavior.