One of my hives seems to want more ventilation. I have the entrance reducer on the 4 in. opening, and about 5-10 bees fanning the entrance constantly, no matter the temperature, and others who are chewing on the entrance reducer, trying to increase the size of the opening, I guess. The bottom entrance is currently the only opening in the hive, other than the screened bottom board. I've been seeing some hive beetles recently; I caught 5 or 6 on some Swiffer pads in this hive as of last inspection. I'm trying to keep entrances to a minimum to help with keeping the beetles out. What would you guys recommend to help increase the ventilation in this situation?