Controlling Odors

In our rat room, next to the TV, we run two HEPA air cleaners
(Honeywell on the left and BlueAir on the right).

One of the most common questions I see being asked about rats is how to keep the smell under control. It is important to control odor. When the cage smells, it is a sign that it is dirty and needs to be cleaned, and the environment is likely less than ideal for the rats and for you as well. This is especially important if the rats are kept in a bedroom where you will be sleeping at night.

The most obvious answer to this question is to clean the cage frequently. It is important to keep the cage clean. Dirty cages can lead to respiratory issues, skin infections via scratches and cuts, weakened immune systems, and other problems. But cleaning is only the answer up to a point. If you clean too frequently and vigorously, you might find that your rats go crazy marking everything. When they find that their smell has been eliminated, they go overtime to undo what you have just done. Because of this, some people recommend leaving a used hammock in after a cage clean or doing spot cleans at times instead of a full cage clean.

Using the proper cleaners can also help. With animals, we like to use natural products, rather than harsh chemicals that may contain irritants or fragrances. Plain white vinegar is an excellent choice for cleaning cages. It has a powerful effect for neutralizing odors, especially urine odors. It can be used to clean the cage and it can also be added to the rinse cycle when you wash liners. Liners can begin to retain that urine odor over time, but adding vinegar to the machine when they are washed will prevent that from happening. If you have a front loading machine, you can add the vinegar to the fabric softener dispenser and it will be added to the rinse cycle at the appropriate time automatically.


Cage size and number of rats will also affect the smell. If you have a larger cage and you do not fill it to capacity, you can go longer between cleanings without noticing excessive smell. I always like to keep my cages half stocked with regard to the number of rats the rat cage calculator says will fit in that space.

What you use as bedding can impact how quickly the cage smells. If you use litter on the bottom of the cage and the cage gets stinky fast, you might want to try switching litters. Some work better than others. I have heard good things about ECO Bedding, but I don't use litter except in the litter box, so I can't offer an opinion.

Many people, myself included, use fleece to line the trays and shelves of the cage. Fleece is soft and comfy and reusable, so it produces less waste (as long as your rats are not voracious chewers). However, fleece alone is not very absorbent. If you use fleece by itself, the pee will wick through the fleece and pool on the pan/tray underneath, where it will start to smell almost instantly. To better control odors, you will want to use something absorbent underneath the fleece (or make liners with an absorbent layer beneath a fleece layer). Towels are one of the best choices for absorbency. The thicker bath towels work better than thin sparse towels. However, towels can be chewed and unravel, making them a more dangerous choice. Another option are U-Haul furniture pads, which are very absorbent but do not have unraveling threads like towels do. They can be easily sewn into liners or just cut and laid on the pans beneath the fleece. Instructions for making these liners can be found in the Tutorials for Common Rat Hammocks and Accessories PDF file or in this post of the blog: Liner Instructions for Critter Nations and Martins R-695 Cages.

Fleece cage liner, with U-Haul furniture pad lining for absorbency

Some people also recommend leaving a cup of vinegar near the cage to help absorb the odors. You can also open a box of baking soda and leave near the cage. I do not recommend sprinkling the baking soda in the cage in the bedding, as the dust may irritate your rats lungs.

Finally, I strongly recommend using an air purifier with a HEPA filter in the room with the rats. I recommend one with both a true HEPA filter for removing dust and allergens from the air and also a carbon filter for removing gases and odors. Air purifiers are rated in terms of room capacity. Make sure you get a purifier that can handle the size of the room your rats are located in. If you want top of the line, I highly recommend the BlueAir brand. We use them in rooms with animals in them because they are very powerful and effective. They could handle my bird room when I was breeding finches in a free flight environment for a conservation program. But for most ordinary situations, the standard Honeywell type home air purifiers will work just fine.

And on an ending note, while I have recommended many ideas that will help you eliminate and remove odors from the environment, the one thing I want to recommend you NOT do is try to cover them up. If the odor is overwhelming, there is probably something that needs to be addressed in the environment. Covering up the odor won't help address that issue. The ammonia/urine vapor will still be in the air. Using scented candles, scented air fresheners, incense, Febreze, or perfumes to cover up odor won't address the problem and will just add harmful chemicals to the environment that can irritate your rats lungs and lead to respiratory problems like myco flare-ups.

A special note on Febreze. Febreze is supposed to be safe to use around pets. While that is likely true for cats and dogs, for birds, it is recommended that they be removed from the room while using the product because of their sensitive respiratory systems. I always recommend rat owners follow the same precautions as bird owners with regard to such products. Birds are at a greater risk and can outright drop dead when exposed to certain toxins in the air (canary in the coal mine type thing), but what can cause death in birds may irritate a rat's respiratory system enough to trigger a myco flare up. Thus, I highly recommend not using Febreze in the presence of your rats or on fabrics that your rats have regular contact with.