Okay, after reading here I realized I might be stressing my male Dumerils by having him in a 40 long tank, and switched him with my ball python. I now have him in a 20 high, on aspen. The new tank has a painted back wall and a curved bark overhang glued hangway up on one side, both of which will help give him a sense of security. He has a hide on the cool end, and bark to burrow under on the warm end, and a water bowl. Should I not handle him till he eats? I'm loath to do that, as he needs to gain trust with us, as he wasn't handled much before I got him. He stopped eating in October, but doesn't seem to have lost any discernable weight. Both my ball pythons and one of my kings are in the winter off-food stage as well. Could this just be a winter thing for him as well?
It seems strange to me to have a 3 foot boa in a 20 high, but I was told they stress in bigger tanks (my ball python is enjoying this switch, though).
Any advice or suggestions are very appreciated! 
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0.1.0 Boa, Elsa
1.0.0 Dumeril's Boa, Bruce
1.0.0 Mexican Kingsnake, Vincent
1.0.0 Graybanded Kingsnak, Boris
1.1.0 Ball Pythons, Pete & Sweetie-Darling
2.3.0 Bearded Dragons, Bela, Sally, Marigold, Phoenix & Spook
1.2.0 Fattailed Geckos, Sahein, Beltaine & Soltice
2.4.0 Leopard Geckos, Ian, Wicca, Rune, Ursla, Ostara & Pagan
2.0.0 Rats, Captian Howdy & Despero
0.0.1 Hermit Crab, Kraken
0.0.1 Pom-pom Goldfish, Jester
1.0.0 Pushy Lovebird Baxter

