My hives are located in Tucson, AZ and we have been experiencing consistently cold nights for the past few weeks (low 40s) and though the bees are able to fly everyday they are in their 'winter cluster' mode as far as Tucson goes. 3 of my hives I went into yesterday had no brood (one had a small patch of eggs) but all 3 hives had queens in them? My question is: Do bees take a break in brood rearing once winter settles in to the point that there is not any brood in the hive at certain times? I looked closely for evidence of a varroa infestation in all three hives but did not see anything. Thanks in advance for any advice!