I wouldn't hide it.
I'd just bring it up in conversation.
Same way as you bring up whether or not you have kids, or an ex, or pets...
discussing common interests, likes/dislikes...just tell her straight out.
Like someone else said already...are you going to get rid of the herps if she doesn't like them? Probably not, right? So, just tell her. She'll accept it and be fine with it, or she may tell you "keep them away from ME!"
For all you know, she may be quite interested in your pets....and it might just be one more common interest that you could talk about.
Good luck to you and your new girl by the way!