Game cameras typically have fairly good water resistant housings. Some are better than others, and we all understand the importance of keeping moisture out of the internal game camera compartment. It can be difficult to combat the effects of moisture, when our game cameras get submitted to the worst elements that the environment throws at us. While nothing may be fail-proof, there are some steps you can take to help control the effects of moisture.
Keep several dry cloths with you when visiting your game camera to swap out batteries or memory cards. Inspect your camera for any signs of moisture, and wipe the interior down to make it as dry as possible.
Consider using small dessicant packs. These are the same little pellet filled packets that you typically find in the box of any electronics component you may purchase. You can usually find these at any electronics store, or at online websites such as eBAY. These packs promote dryness by absorbing moisture. Used inside of a game camera housing, they can be helpful in removing moisture from the inside of your game camera housing.
Avoid changing batteries and memory cards in rainy weather if possible. If this isn't an option, use the options listed above to combat moisture.
When changing batteries, make sure that the batteries are at the same temperature as the camera itself. Batteries carried into the woods in an inside pocket will be warmer than the outside air temperature, and can tend to sweat as they cool inside the game camera. Try carrying them into the woods in an outside pocket or mesh pouch.
I own many game cameras, and this gives me the option to periodically swap out entire camera setups. I like to bring my cameras indoors from time to time to inspect them for damage or worn weather seals. This also allows me to completely dry my camera indoors where I typically have a lower humidity level than outdoors. I can then swap in my dry camera for another game cam in the field.
If you ever see excessive moisture inside your camera while checking it, pull it down. Bring it indoors and inspect it for signs of a leak. Game cameras are an investment and can be used over a long period of time if they are properly protected and cared for.