How big should your gerbil cage be? If you’re not sure, you’re not alone; there are lots of different opinions out there on this topic, and they vary widely. The size of your gerbil cage or tank is the first step in ensuring that your pets have a happy and healthy life free from stress and boredom.

Below, we’ll look at the best gerbil cage and tank sizes below so you can make an informed and educated decision about what’s best for your pets.

What’s the Best Gerbil Tank or Gerbil Cage Size?

Consensus: You should aim for 20 gallons per gerbil or a floor space of at least 620 square inches for two gerbils.

The size of your gerbils’ enclosure can make all the difference between whether they’re happy and healthy or not. The size of your gerbil habitat depends on where you’re keeping it in your home, as well as your budget. But most of all, it should depend on what your gerbils need in a home.

Minimum gerbil cage size

Gerbils who live in a cage that’s too small are prone to acting out and becoming depressed (we’ll cover some signs to watch out for below).

The rule of thumb recommended by small animal experts and real gerbil owners is a minimum of 10 gallons of space per gerbil. However, most experienced gerbil owners believe that 20 gallons per gerbil is a much better benchmark.

Is a 10-gallon tank large enough for gerbils?

A rectangular 10-gallon tank usually has the dimensions of 20” L x 10” W x 12” H, which may work for one gerbil. However, gerbils shouldn’t live on their own and should always be in pairs or small groups, so this size tank doesn’t work for gerbils.

Some small animal sites recommend a 10-gallon tank for up to two gerbils, but that size is just too small.

Even if you add a tank topper to a 10-gallon tank, it’s typically too small for two gerbils to live in happily. We do not recommend using a 10-gallon tank with a topper for your gerbils.

Is a 20-gallon tank large enough for gerbils?

A standard 20-gallon tank is large enough for two gerbils, technically speaking. It provides 10 gallons per gerbil, which is the recommended minimum.

However, the problem with 20-gallon tanks is that there’s little room for the enrichment that your gerbils need, such as a 9-inch wheel (or larger), a hideout, a water bottle and food dish, and sufficient chewing materials.

If you section off part of the tank to place enrichment items, you aren’t left with enough burrowing space for your gerbils.

This arrangement can work for gerbils who don’t like to use a wheel, such as elderly gerbils. However, it’s not ideal for young, healthy, and active gerbils.

You can make a 20-gallon tank work for two active gerbils by adding a tank topper. However, 20-gallon tank toppers currently have to be custom-made and can be quite costly.

Here’s an example of a great 20-gallon tank topper that you can use to house your gerbils’ wheel and water bottle and provide more play space. Make sure to measure your tank to ensure that any topper you purchase will match its dimensions.

Bigger is not always better

If you peruse gerbil care forums, you may find many posts implying or insisting that no tank or enclosure is too large for gerbils. The more space, the better.

But this isn’t always the case. Give your gerbils too much space and too many hides or separate areas, and your gerbils are more prone to declanning. This can lead to fights between your gerbils and eventually injury or death.

The maximum amount of space you should provide your gerbils, according to most authorities, is 20 gallons per gerbil, or a 40-gallon tank for two.

Most gerbil owners would agree that it isn’t necessarily the amount of space you provide your gerbils but what you have in that space that leads to declanning. For instance, filling up a large tank with too many hides can lead to declanning.

Having issues with territorialism is more likely with large enclosures because there are more individual areas to claim and get defensive over. The biggest things that lead to declanning are a single food dish, a single way in/out of important areas, and separate compartments and spaces.

Learn more: Best Gerbil Cages and Enclosures

Is Your Gerbil Tank Too Big or Too Small?

Consensus: Biting and chewing on bars or excessive scratching can indicate a tank that’s too small. Declanning is a sign of a tank that’s too large or too divided into separate spaces.

If you already have gerbils in an enclosure, you might be wondering if your gerbil cage or tank is too small or, alternatively, too large. Here are some signs to watch out for that can tell you if your gerbils are in the wrong size habitat.

Gerbil cage is too small

What happens if your gerbils are in too small of a tank or cage? Here are some behaviors you might notice if your gerbil enclosure is too small:

• Climbing and biting cage bars
• Excessively digging at the glass (some glass-digging is normal)
• Acting lethargic and depressed
• Gerbils squabbling with each other excessively
• Not running, jumping, digging, or playing

We’ll let you know what you can do now and in the long run if you find yourself with a tank that’s too small, here.

Gerbil cage is too big

The biggest risk of a habitat that’s too large is your gerbils declanning. Declanning is essentially when gerbils start to treat each other as outsiders, which can be extremely dangerous for the gerbils. Declanning can happen with as few as two gerbils.

Keep an eye out for these signs that your gerbils may be starting to declan:

• Staking out separate territories
• Not letting one another pass within tubes and tunnels
• Exessive chasing around the enclosure, especially when it’s always one gerbil doing the chasing and not the other
• Defending the food dish or stash against the other gerbil
• More squeaking and thumping than usual
• Sleeping in separate areas

If your gerbils are showing signs of declanning, it’s essential to separate them quickly. This situation can be reversed, and your gerbils can become bonded again. But it’s important to separate them first so that no one gets hurt.

What to Do if Your Habitat is Too Small

Consensus: You’ll need to get a larger habitat; but for now, giving your gerbil time outside the enclosure can help.

Unfortunately, most of the “gerbil cages” and tanks that are available commercially are actually too small for gerbils. If you’ve wound up with your gerbils in a habitat that’s too small, you’re certainly not alone.

Luckily, this issue can be resolved relatively easily, so there’s no reason to feel guilty over this common issue! Here’s what to do if your gerbil tank is too small.

Know that your gerbils are OK

Your gerbils are resilient, and they live in harsh conditions in the wild. Although they don’t enjoy living in cramped quarters as much as they enjoy the proper amount of space, you haven’t permanently scarred your gerbils by keeping them in a small space. And they don’t think you’re a bad gerbil owner!

Give your gerbils time to run free

The best thing you can do right away if you’ve found yourself with a habitat that’s too small is to give your gerbils the opportunity to stretch their legs.

Block off an area where they can run free. You can use a small animal pen to make setup easier.

You can set out some obstacles, toys, and treats around the area you’ve blocked off to encourage their natural curiosity.

Important note: Gerbils may be burrowing critters, but they can jump more than 18 inches horizontally or 6 inches vertically. Make sure that you keep an eye on your gerbils and block off an area with boxes or a pen that’s sufficiently tall.

Take your time choosing a new enclosure

You might feel like you need to go out and buy a larger gerbil cage or tank as soon as possible. However, this can often result in another enclosure that’s not large enough or, alternatively, one that’s too big.

Take your time choosing the right habitat that will work for your gerbils, and know that you can temporarily overcome the current size issue with plenty of interaction and playtime with your gerbils.

Learn more: Is the Omlet Qute a Good Cage for Gerbils and Hamsters?

Types of Gerbil Enclosures: Cages vs. Tanks

Consensus: Choose a tank with the proper type of lid, or a cage with a deep bottom for digging.

Gerbils require lots of room to dig and burrow, which means a cage with open bars doesn’t work very well. You can make a cage work for gerbils, but you’ll end up with more of a mess than you would with a glass tank.

What to look for in a cage

If you want to keep your gerbils in a habitat with more open air than a tank, you can choose a cage. But you’ll need to find a cage that’s large enough and includes a deep bottom that can be filled with bedding for burrowing. It’s key to provide your gerbils with a substrate that’s at least 6-8 inches in depth for digging and burrowing.

What to look for in a tank

Not all tanks are suitable for gerbils, but most can be altered to work. A typical 20-gallon aquarium tank will come without a top or with a top that’s intended for fish. Aquarium tank lids won’t work for gerbils because they’re made of easily chewable plastic and don’t offer enough airflow into the tank.

Instead, you’ll want to look for a tank lid that’s intended for rodents or reptiles, with a breathable metal mesh. Alternatively, you can purchase a tank topper for the tank or create a lid out of wire mesh.

Although plastic enclosures can sometimes work, glass is preferable to avoid gerbils chewing on their habitat and potentially getting out.

DIY gerbil habitat

Many experienced gerbil owners build their own gerbil enclosures using storage bins or other pieces of furniture. If you’re a fan of DIY projects, you can create the gerbil enclosure of your dreams for a relatively low cost.

Just remember to keep the habitat within the proper size for the number of gerbils you have and provide everything they need (and not too much).

Upgrading or Changing Gerbil Tanks

Consensus: Help your gerbils settle in by bringing familiar smells and limiting the introduction of new features.

If you need to transfer your gerbils to a new tank, you can make the process less stressful for them by taking a small amount of their old bedding with them into the new habitat. This way, they’ll have some familiar smells with them to assure them they’re in safe territory.

Arrange the tank or cage as similarly to their old one as possible, and don’t add too many new toys, ledges, or hideouts at once. If your gerbils have a stash of food in their current habitat, transfer that stash to the new enclosure, too.

Choosing a Tank That Makes Your Gerbils Happy

As humans, we might look at a gerbil cage or tank that’s the proper size and think it looks too small, cramped, or simple.

But gerbils aren’t people, and they don’t require a mansion of a cage or tank to be happy. In fact, too much space and too many activities can overwhelm and stress your gerbils almost as much as a habitat that’s too small.

Ultimately, you’ll be able to tell if your gerbils are in a habitat that they enjoy. Equally important as the size of the enclosure is the quality time you spend with your gerbils, including plenty of time to run, stretch their legs, and explore outside of their home turf.