Re: Mouse guard
SunnyR, If you have highs in 70's no need to put mouse guards in. Bees are still flying, they will take care of any mouse that sneaks at night. I won't put mouse guards until daytime temps are consistently below 50's. If your hives are strong no need to reduce entrance even if you are feeding. They know how to defend from robbers. Their strength is in the numbers.
I normally change the size of the opening depending on hive strength and time of the year. I like to keep them open more than some beekeepers that I know. The reason is that I believe in proper ventilation of the hive leads to its survival. But there is a secret. All my hives have slatted racks. I believe that they are an important part of over wintering on northern climates.
USDA Zone 7a - elevation 148 feet