You want some air present to aid in the curing process, really the buds still got a bit of life left in em' despite the fact that they have little water left. Theres a few different chemicals in the buds that are inactive, and with proper curing they become the active chemicals that we love so much. Fresh air helps them convert these chemicals for us. But too much air will make your bud go stale, so dont put too many of very big holes in your containers, just something to allow some air exchange.