Besides a communicable fungus that's usually seen only in wild snakes, there's nothing I'm aware of that can really devastate a collection of colubrids like that. There's not been much research done on it, but there's no known cure and it seems to be highly contagious; a real worry though since a lot more colubrids are wc than constrictors (at least here in the US).

I actually do something similar since my parents are sort of into snakes as well (and have had a wonderful extra room since I moved out). Currently waiting for the QT to finish up on a female garter they're loaning me to breed this season... I feel like it usually goes the other way, where they'd keep my male, but I have better luck with getting the young ones started eating.