Snookie, If it was a package of bees that you put into the hives then the answer i'd give you at this point is go with the larger opening, however don't remove the reducer. You will want some extra ventilation at this point but not so much that it causes problems. Until the entrance reducer starts causing problems like so many bees coming and going that they can't easily get through, keep it in place. It takes at least 21 days from package insertion to first adult bees emerging. Even if you have a very prolific queen that layed 1000 eggs that first day, you won't have the population to handle a wide open entrance at this time. I have 10 hives right now in WV with 70's temps with reducer in and set to large opening. Bees have been hived for 17 days at this point, and i don't plan to take the reducer out till they are at least at the 42 day mark which is the time of one complete brood cycle.