Re: Ask Questions Here!
I too get people I sell bees to, with top bar hives, telling me the bees absconded, often. So much so, that were at all possible I'll go there and do the install myself.
Very often, the problem is caused by overheating. The new bees do not have their ventilation system sorted out till after some days. Mean time, if the sun shines on the hive, it gets warm, the bees leave. Simple fix, put something such as cardboard over the lid, with an air gap underneath, to shield from the sun.
Do this, leave the queen in the cage for the bees to release slowly, and get all the bees in the hive properly, not hanging under the screen if there is one, and success will be close to 100%.
PS. Blocking bees in is totally disruptive to them and should be avoided where at all possible.
44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).