I keep the eggs in Glad type disposable plastic and I don't put any holes in them and that holds in the humidity. Just exchange the air now and then by opening up the lid once or twice a week. I've heard of folks who only "burp" them once every 2-3 weeks. If you do the air exchange and don't put any holes in, it works just great. I "naturally" burp them quite often because I am curious and just want to take a peek!