Humidity is often a concern with keeping reptiles, but often, the problem is getting and keeping humidity high enough. At times, though, there can be difficulty in keeping the humidity low enough. For snakes in particular, humidity that is too high can lead to scale rot (a bacterial infection which can lead to death if left untreated); therefore, it's important to make sure the humidity is in an optical range for your specific species.

To begin with, it's always important to do your research prior to owning any animal; different snakes will have different requirements. It's best to mimic your snake's natural habitat as closely as possible, and they all live in varying microclimates.

What is Humidity?

Humidity is defined as the amount of water vapor in the air. The amount of moisture in your snake's enclosure is determined by a combination of temperature, ventilation, and the amount of water vapor in the air.

Snakes usually live in a more humid, warmer environment. The natural moisture in the air helps their skin and respiratory tract to stay moist. It is best to mimic their natural habitat as closely as possible.

The easiest way to measure humidity is by using either an analog or digital hygrometer. If you are using a hygrometer with a probe, a good way to measure is to place the probe where your snake spends most of its time (on the substrate, tree branches, ets.)

Steps for Lowering Humidity

Luckily, if you're finding that your humidity needs to be lowered, there are a few ways in which you can achieve this:

1. Increase the ventilation in your enclosure. This may entail replacing a glass lid with a screen or partial screen lid, drilling holes in a plastic tub, etc.
2. Replace the water dish with a smaller one and/or move it to one end of the enclosure. Keeping the water dish on one end will also help with keeping a temperature gradient available to your snake(s); the dish should be placed on the cooler end.
3. Add a dehumidifier. If you live in an area where humidity in your home might be naturally higher or you are struggling mightily with getting the humidity correct, you may want to consider a dehumidifer. You will need to keep an eye on the humidity levels while it is operating and turn it off appropriately, of course, but there are some smaller dehumidifiers made for reptile habitats.
4. Look for a drier, more moisture-absorbing substrate. Some substrates will naturally retain more moisture and, therefore, maintain a higher humidity in the snake's enclosure. Drier substrate will soak up more moisture and help keep humidity lower.
5. Replace a plastic enclosure with a glass one, as plastic will hold humidity more than glass will.
6. If you're using a heat mat, you may want to consider switching to a ceramic heat emitter or heat bulb. This will help dry the air from above; a heat mat on the bottom will encourage any moisture on the bottom to evaporate and can increase humidity.

As stated previously, the best thing to do is plenty of research and knowing a snake's individual needs before purchasing, which allows you to set up an enclosure in advance and make any necessary adjustments before possibly subjecting your pet to an incorrect temperature or humidity level.

Links of Interest:

https://www.zillarules.com/articles/top-amphibian-reptile-mistakes-to-avoid

https://cyfairanimalhospital.com/snakes/snake-owning-101-heat-humidity-habitat/#about