Personally, I would keep lids on and just burp em every so often. Let the ladies get acclaimated to the dry air. Introduce them for longer intervals until they no longer fit in the cup. Kinda training them to the environment. I try my best to keep RH above 50% with babies in the room. I definitely shoot for higher, but that isn't always possible.Thats cool love your garden. Regarding my humidly question, what's the rule of thumb please?