Corn snakes do need humidity—but not a lot. You should use a hygrometer to make sure that the humidity in your corn snake’s enclosure stays between 40 and 50 percent.
That is high enough that your corn snake won’t have problems shedding and low enough that there won’t be unnecessary issues with skin infections and breathing.
In this article, we will tell you why corn snakes need humidity at the 40 to 50 percent level, and how you can be sure to give them just the right amount of moisture for healthy living.
Corn Snakes Come From Well-Watered Areas
Corn snakes are abundant in the Mississippi Valley and the Southeastern United States.
These are all areas that get lots of rain, distributed more or less evenly throughout the year. There are many lakes, streams, and marshes.
In that humid climate, corn snakes prefer drier areas.
They make burrows in dried grass and leaf litter, waiting patiently for days at a time for a lizard, a frog, or, more often, a rodent to scamper by. They strike it and eat it whole.
On average, the morning humidity in areas where corn snakes live in nature runs around 85 percent. By the middle of the afternoon, humidity is down to 50 percent. Morning humidity is enough to condense into dew.
Humid mornings ensure that corn snakes get the moisture they need every few weeks to shed their skins.
But you don’t want to give your corn snake exactly the same humidity it encounters in nature.
If you humidify your corn snake’s enclosure so much that condensation forms on the glass walls of its terrarium, it won’t evaporate during the day.
Dripping condensation will accumulate in the substrate of the cage. It will start growing mold, and your snake will be at risk of getting fungal infections of the skin.
A constant 50 to 60 percent humidity, not so much that there is condensation in the cage, is best for keeping your corn snake healthy.
Here’s How to Keep Humidity and Healthy Levels for Corn Snakes
The secret to giving your corn snake the humidity it needs involves keeping several factors in balance.
First of all, your corn snake needs warmth. Corn snakes and other reptiles are cold-blooded.
They depend on the atmosphere around them to keep their bodies at a survivable temperature.
You should never let your corn snake’s enclosure get cooler than 70 degrees Fahrenheit (21 degrees Celsius).
Your corn snake needs a basking area, where it can digest its food (digestive enzymes require higher temperatures) at about 85 degrees Fahrenheit (29 degrees Celsius).
These temperatures support your snake’s metabolism, but they also encourage slow evaporation.
The next requirement for your snake’s cage is good ventilation. All reptiles need oxygen. You can’t seal them up in a terrarium and expect plants, which they will promptly destroy, to keep the air breathable.
The other reason for good ventilation is making sure that there is enough air circulation to keep moisture from accumulating inside the cage.
The best way to take care of this is to have a wire mesh grate for a lid on the cage. Or, better, have a wire mesh door on the side of the cage for ventilation and easy access to your snake.
Corn snakes are great escape artists. Any mesh lid or door needs to fit securely, leaving no cracks, and come with a lock. Young corn snakes can wriggle through any opening the size of their snouts.
Proper heating and ventilation keep moisture from becoming excessive, but how do you generate just enough humidity for your snake?
You will need two things:
- A water bowl, that you clean and refill with fresh water daily, and
- A bowl of damp moss.
The evaporation from the water bowl and the damp moss will be enough to keep humidity at 50 to 60 percent. At this level, your corn snake’s skin stays moist and supple.
The skin between the scales does not crack and it does not become infected.
The immune system in the skin of your snake is more active, and better able to fight infection. And it is easier for your snake to breathe, giving it better chance of survival in case of respiratory infection.
It’s OK to soak your snake in its water bowl if it seems to have trouble shedding. Chances are, though, it will do this on its own.
You can minimize any problems from accidentally giving your snake too much humidity by being careful to keep its enclosure at the right temperature. Have a thermometer mounted inside the cage.
Add a hygrometer to your snake’s enclosure, so you can keep tabs on humidity.
How Can You Tell If Humidity Is a Problem?
Occasional variations in the humidity of your corn snake’s enclosure are not likely to cause serious problems.
But letting the humidity run too low or too high for an extended period can result in visible problems in your snake.
Low Humidity Problems in Corn Snakes
Keeping humidity levels high enough can be a problem if you live in a desert climate.
Low humidity can plague your snake if you use forced-air heating for your entire home during the winter.
In desert climates or extreme low-humidity conditions, consider using a humidifier for the room where you keep your snake. Extra humidity will prevent problems such as the following.
The most common complication of low humidity for corn snakes is difficulty shedding. The snake may not be able to remove patches of skin on its body. It may retain caps of skin over its eyes.
Don’t start yanking on skin to “help” your snake shed. Instead, soak it in a bowl of warm water for 20 to 30 minutes.
When you take it out of the water, dab mineral oil (available from a pharmacy, this is not the oil you use in your car) on the caps on its eyes, if they have not fallen off.
Retained skin and eye caps should fall off in 24 hours or less. If they do not, repeat this procedure.
Corn snakes have a single, long lung. Low humidity can dry out the linings of its bronchi so they crack.
This makes them more easily infected, especially with bacteria that can be found in unsanitary cages.
The first sign that your corn snake has a respiratory infection is usually holding its mouth open to breathe.
It may also wheeze or make crackling sounds as it breathes. It can have a yellow or green discharge from its mouth and nostrils.
Increasing humidity to 50 or 60 percent reduces your snake’s susceptibility to respiratory infections.
You should not use a vaporizer once your snake gets sick, the way you might for a human. Take your snake to the vet for treatment.
High Humidity Problems in Corn Snakes
Parasites and infectious microorganisms take advantage of high humidity.
Mites are eight-legged arachnids, related to spiders, crabs, and scorpions. You may see tiny red or black dots moving on your snake’s chin or in the pits on the sides of its head.
Severe infestations of mites can cover your snake’s entire body.
Mites can drain your snake of so much blood that it becomes anemic, or transmit infections like inclusion body disease.
Mites prefer a humidity of 80 to 85 percent. This level of humidity makes your snake’s skin moist and supple, easy to penetrate.
Lowering the humidity to 50 percent tightens your snake’s skin enough that it becomes resistant to mites.
Snake Fungal Disease
Wild-caught snakes in the United States are frequently infected with Ophidiomyces ophiodiicola , the organism that causes snake fungal disease.
This fungus produces skin ulcers that crust over. There can be nodules under the skin that keep your snake from shedding.
Your snake’s eyes can become cloudy, and there can be so much tissue damage around the mouth that it can no longer eat.
Snake fungal disease is highly unlikely in captive-bred snakes.
But if you adopt a corn snake captured in the wild, you need to isolate it from other snakes, and keep the humidity in its enclosure under 50 percent.
Frequently Asked Questions About Corn Snakes and Humidity
Q. What is the ideal humidity to support easy shedding for a corn snake?
A. Corn snakes don’t need to soak in a water bowl if the humidity in their enclosure is 65 percent.
But the easiest way to achieve this level of humidity is to make sure their water bowl is full of clean water at all times.
Q. How many air holes does my corn snake’s cage need for proper humidity?
A. If you have your corn snake in a 37-quart Sterilite plastic gasket box, it will need about 280 small air holes for adequate ventilation.
The air holes should be smaller than your snake’s nose. It is best to buy an enclosure with a wire mesh lid or door.
Just be sure the lid and the door have a lock. Monitor humidity with a hygrometer to make sure you have it right.
Q. What is the easiest way to lower humidity in my corn snake’s enclosure?
A. Give it a smaller water bowl. If the humidity goes too low, then put the larger water bowl back inside.
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