It has been extremely cold here; listened at one hive, didn't hear anything with the stethoscope, peeked in and the bees were very active around the center hole in the inner cover and on top of the inner cover. I had used a 2" shim and tacked #8 hardware cloth on the bottom and filled with a sugar mix of water and a little HBHEALTHY that hardened; this was set on top of the frames in the upper brood box and the inner cover over this then the outer cover. The was done back in November. I am not sure what to think about this; should I be concerned? Thanks.