you said it yourself - humidity! Keep the humidity as close to 100% as you can. That should solve your problem 
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1.2.2 normal ball pythons (Cindy, Darwin, Periscope, and dah bebbies)
0.2 rescue chinese water dragons (Yoni and Linga)
1.0 rex rat (Scurvy)
1.0 gerbil (Yerbul)
0.1 mice (Cute Girl Mousy)
0.1 bunny (Spazz)
1.1 betta fishes (Vicious and Killer)
2.2 great danes (Shasta, Odysseus, Merlot, and Watson)
1.0 fat fuzzy mutt (Smokey)
1.1 cats (Thidwick and Turtle)
3.0 horses (Buddy, Sam, and Scout)
1.0 goat (Billy Jack)
0.0.1 chupacabra (it ate our chickens)

