how to rescue it without ruining the wall .
Regards,Terry.
I guess I'd better try to answer your question before asking you one. So here it goes.
First of all, there must be an entrance that you can somehow apply a cone to. Maybe several. So you want to close off all but one hole. Then figure out how to attatch a cone to the wall covering the remaining hole. Maybe caulking tube of glue would work? Ora cone through a wooden base and then glue that to the wall. Then you need to set up a hive for the trapped out bees to go into. And there are lots of places to learn about that. Do a search at the Search place on the bar above this Thread.
So, here's my question. Since you used the word "rescue", do you think that they are in danger or in the wrong place oor do you just want to have them in your equipment so you can use them for your ends? which is what I do w/ my bees, I guess. I'm just curious.
What if you left them there and set up a swarm catching unit to catch swarms from this colony? Then, if it is the genetics that you are after, you would have them. Maybe not on your schedule, but on Natures schedule.