I have 3 hives:
Hive 1 - came out of winter strong - recently split into hives 2 and 3 (Monday 5/12). Loaded with bees. I just put a second deep on a week after split and put a super/excluder on after that to alleviate crowding. Inspection yesterday showed 7 frames of brood in bottom box, no brood in top deep, and new comb formation only in the super. Bees everywhere. Lots of nectar and pollen. Some honey. No swarm or supercedure cells. I did an alcohol wash mite test on Hive 1 yesterday. Only had 1 varroa mite in the bottom of the test jar. This was the same result as 2 weeks before. I'm holding off on putting in the oxalic acid sponges.
Hive 2 and Hive 3 - split from hive 1 and put in purchased queens 11 days ago (Monday 5/12). Released queens from cage into hive 4 days ago (Monday 5/19). There are lots of bees in both hives. I put on second brood box es with food frames on both hives because I was concerned that they may be running out of food. I did not pull any frames so as to not disturb the new queens.
Normally there is not a lot of traffic out of 2 and 3 but some. Hive 1 is always very busy and more so as it warms up during the day.
I work in my shop within view of the hives. On 2 days, I have looked up and seen massive amounts of bees around Hive 2 and Hive 3. They will be at Hive 2 for a while and move to Hive 3. I am nearly certain this is Hive 1 robbing these hives. I put on robbing screens.
Today again, I saw a cloud of bees on and around hive 3. I closed down the top entrance to the robbing screen and took out the block that holds the upper cover a little off the inner cover. The cloud went away. I put the lifting block in and observed through the hole in the inner cover that there are still bees in the hive.
I intend to inspect hives 2 and 3 on Monday to see if the new queens are laying. I did see pollen going into hive 2 but not into hive 3. I think that is a good sign for hive 2.
I have lost hives a couple of times to robbing so I am sensitive to the topic.
Any ideas or suggestions? I am thinking of screening the hole in the inner cover and blocking the notch in the inner cover. This should allow ventilation but prevent bees leaving and entering the top of the hive.
As an aside, I lay down scrap industrial conveyor belt under my hives to control grass and weeds. I trim the belt to go around the legs of the hive stands. It also helps to be able to see bees on the ground under the hive or any carcasses. I think you could find some similar material at Home Depot. Cardboard boxes would work in dry weather.
Thanks for any advice!
Charlie Garrott