Michigan doesn't have enough humidity? You have all those Great BIG Lakes? So what does humidity and catching bugs have to do with one another? I'm about to have another one of
these.
The potting medium should be providing enough humidity (they grow in bogs!) and bugs are an added attraction. They don't NEED to catch bugs. That is an added bonus. You can actually kill your plants by force feeding them bugs (over fertilizing). They are really easy plants to grow. Let your plants do their own thing!
I live in the desert - humidity often drops to 0 (really - ZERO). My plants are fine.
Daisy