why do snakes need humidity?
Snake Vivarium Setup

How to Lower the Humidity in a Snake Tank

Some herpetologists find it difficult to keep the moisture level down in their snake’s enclosure. If the air in your snake’s tank is too damp, this has implications for the health of your snake. For example, your snake could develop scale rot, which is a nasty bacterial infection of the ventral (belly) scales.

How do you lower humidity in your snake’s vivarium? Replace the water bowl with a smaller one, and move it to the cool end of the enclosure. Create some ventilation holes in your vivarium’s lid, or replace the lid with a mesh screen. Switch to a drier, moisture-absorbing substrate (aspen or paper bedding.) Use a fan or dehumidifier in the room where you keep the vivarium.

We’ll let you know why snakes need moisture and the humidity level (percentage) that is optimal for each species of snake. All snake breeds have different requirements. We’ll explain how to measure humidity levels, and provide some advice and tips for lowering your snake tank’s humidity level.

Why Do Snakes Need Humidity?

The term “humidity” describes how much water vapor is in the air. Climates with plenty of rainfall, plant life and high temperatures (such as rainforests) tend to be very humid. Deserts typically have very dry air, and many environments are somewhere in between.

All animals require some level of humidity in the air to remain healthy. Most species of snake require slightly higher humidity than you’d have in your house.

That’s because many snakes come from a damper, warmer environment than humans. The moisture in the air helps their skin and respiratory tract to stay moist.

A snake in an excessively dry environment will become dehydrated. This may result in several different health problems, including:

  • Dysecdysis (problems shedding the skin)
  • Anorexia (a refusal to eat) and regurgitation, leading to weight loss
  • Upper respiratory tract infections

Snakes are far more accepting of too much humidity than too little. But if the environment is too moist, this can result in a type of infection known as scale rot, or blister disease.

According to the Veterinary Medicine Journal, scale rot can lead to death if left untreated.

How Much Humidity Does My Snake Need?

So, getting the humidity level correct inside your terrarium is very important for your snake’s health. The specific level of humidity that your snake needs will depend on the species of snake.

To fare well in captivity, the humidity level in your snake’s enclosure should mimic that of their natural habitat.

The Western hognose snake, native to the dry North American deserts, thrives with very little moisture in the air (30-50%).

Brazilian rainbow boas, of the South American rainforests, require very high levels of humidity (70-80%). Here are the humidity requirements for the most popular pet snakes:

Snake Type Approximate Humidity
Western Hognose Snake 30-50%
Corn Snake 40-50%
Milk Snake 40-60%
California Kingsnake 50-60%
Ball Python 50-65%
Reticulated Python 60-70%
Boa Constrictor 60-75%
Brazilian Rainbow Boa 70-80%

Your snake will also require slightly more humidity during the shed cycle.

How to Measure Humidity in a Vivarium

You won’t be able to estimate humidity by just looking or feeling inside the vivarium.

The only visual clue of humidity is condensation appearing on the walls of the enclosure, but this only happens when humidity is around 100% (which is far too wet for practically any snake).

The only accurate way to judge your enclosure’s humidity level is to purchase a hygrometer. This is a device which measures the amount of water vapor in the air, and gives you a percentile reading.

You can buy both analog and digital versions. The kinds with a probe tend to be the most accurate. Place the probe just above the substrate, where your snake will be spending its time, to get the most precise reading.

If you own a snake which prefers a drier atmosphere, such as a western hognose snake or corn snake, you’ll need to take steps to optimize humidity levels for your pet snake.

How to Get the Humidity Down in a Terrarium

If you want to decrease humidity in a snake cage, this can be a slightly tougher problem to fix. So, if your enclosure’s humidity too high, you should do the following:

1) Move the Water Bowl

Most snake vivariums have a “cool end” and a “warm end.” The warm end will be the end which is heated, either with a UTH (under-tank heater) or an overhead heat emitter. This provides your snake with a heat gradient, enabling him to regulate his body temperature properly.

If your snake’s water dish is currently sitting on the warm end, start by moving it to the cool end. According to Science Daily, evaporation (the process by which water vapor enters the air) happens more quickly at higher temperatures.

Keeping the water dish cooler will lead to lower humidity in the enclosure.

2) Use a Smaller Water Bowl

If moving the water bowl to the cool end of the tank doesn’t do much, you could also try replacing the water bowl with a smaller one.

We’d recommend that the water bowl is big enough for your snake to be partially submerged in, should it feel the need to bathe. Reducing its size by even an inch in diameter will provide less surface area for water to evaporate from.

3) Increase Ventilation

Persistent problems with humidity can usually be fixed by increasing your vivarium’s ventilation. Warm air rises, so creating some holes and vents in your snake’s enclosure will allow the humid air to escape, and cool, drier air to flow back in.

If your snake is living in a plastic tub, this will be as drilling some small holes in the lid and sides. Alternatively, you could replace the plastic lid with a mesh screen, which will allow for much more ventilation. Just make sure that the screen is securely in place, so that your snake can’t escape.

4) Switch from a Heat Mat to a Heat Lamp

Are you heating your snake’s vivarium from above, or from below? There are various methods of providing snakes with heat.

Some, such as heat mats and heat tape, provide heat from below. Others, such as ceramic heat emitters and heat bulbs, send heat down from above.

Your vivarium’s environment will be drier if you heat it from above than from below. A heat mat encourages any moisture on the bottom of the vivarium to evaporate, increasing humidity.

A heat source projecting downwards into the vivarium will dry the air out. Try swapping your heat mat for a ceramic heat bulb; though ensure that the humidity doesn’t fall too low.

5) Get a Dehumidifier

Depending on a) the area of the world in which you live, and b) your home environment, it could be that the humidity levels in your home are too high for your snake.

If that’s the case, consider buying a dehumidifier to keep in the room that your snake’s enclosure is in.

You can also use an oscillating fan, pointed at your snake’s enclosure, to help move the humid air away from the area when it escapes the vivarium.

6) Switch to a Glass Enclosure

Plastic enclosures tend to hold on to far more humidity than glass terrariums. This is because plastic is much better for retaining heat, and a warmer environment will naturally be more humid.

If you keep your snake in a plastic tank and you are struggling to bring the humidity down, try switching to a glass one, or a wooden one with glass doors.

Closely monitor the enclosure’s temperature to be sure it doesn’t fall too low for your snake.

7) Change the Substrate

The substrate (bedding) that you use on the floor of your snake’s vivarium can have a significant effect on the humidity inside.

Some types of bedding are naturally damp, and tend to disperse lots of moisture into their air. Others are drier, and can “soak up” moisture from the environment, keeping the air dry.

Let’s now have a look at the best substrate choices for controlling humidity.

decrease humidity in snake cage

What’s the Best Snake Substrate for Humidity Control?

The right substrate for your snake’s vivarium depends on your snake’s preferred humidity levels.

There are some kinds of bedding which naturally infuse moisture in the air, and others which draw moisture out, creating a drier environment.

If you’re trying to keep humidity down in your snake’s enclosure, there are three good beddings you can select from which won’t add additional moisture to the air.

1) Aspen

Aspen bedding is a wood-based substrate made from shavings of the aspen tree. It is one of the most popular beddings used by snake owners.

It’s cheap, easy to clean, and it also does a great job at soaking up moisture. Aspen bedding is quite dry and will soak up any water spills or urine, stopping them from leeching into the air.

2) Newspaper

Newspaper is the simplest and easiest to deal with bedding for snakes. It’s widely available and very affordable (if you receive a free daily paper).

A few layers of newspaper at the bottom of your snake’s tank will not necessarily soak up moisture, but it certainly won’t give out any of its own. Change it regularly to ensure that it remains dry.

3) Paper Pulp Bedding

Paper-based bedding, such as Carefresh, is usually marketed towards small animals, such as hamsters. However, it works well for snakes too.

It’s extremely absorbent, more so even than aspen, so it works well for snakes that prefer drier air. However, it is the most expensive option for reducing the humidity in a snake tank.