What to Do About Honey Bees in Your Wall
by R. Preston McAfee, March, 2016
I got a frantic call from my wife: there is an enormous swarm of bees in the yard.
Warning: I have no particular expertise in this topic, beyond having dealt with exactly one hive successfully.
Apparently a spring swarm of bees isn't unusual. Bee colonies fill up, and at some point a queen, along with two to ten thousand supporters, carry a bunch of honey to a new location. They may not find the location immediately, so the presence of a swarm is not a proof that they have chosen your house to relocate. As a result, a call to pest control is met with "wait a few days and see if they leave." I'm confident that if the bees are going into your wall, they have chosen their location and are not scouting for an alternate location.
Bees are necessary; if they aren't in your walls, consider leaving them be. If you want to get rid of them, see if anyone will take them. Allegedly they will sometimes take them for free. Good luck with that.
Pest control services in southern California seem completely inept at handling bees. One of them made up some story about being chased away by the bees, I suspect to soften us up to an exorbitant price quote. Another promised to call back the next morning, and never called back. Overall my sense is that these companies prey on people who are terrified of bees.
If they are in your walls, here is my advice. Locate where they go in and out. This is really easy to do; a swarm of bees means that they are coming and going at least 15 per minute, so their route in and out is readily identified. You are looking for a spot that they go in and out. In my case, they were landing on a piece of wall and then crawling in a hole created by termite damage (we had tented a shed a couple of years ago and killed the termites). Wait until night. The bees will quit flying at night. Rig up a 5 HP shop vac next to the hole the bees go in. This is best accomplished with a second person holding a flashlight who will also spot any active bees. (We had none at night.) When the bees become active in the morning, turn on the shop vac. I had to adjust mine slightly to reliably suck in the bees. Just leave it running until the bees go quiet at night. I got half the bees in the first day. My advice is to do this for several days straight, indeed, until you see almost no bees. Most of the bees won't survive being sucked up by a shop vac but a few will.
During the first night, try to listen to the wall and identify roughly where the hive is located. If you have a mechanics stethoscope, you can easily hear them -- they make a racket. But just putting a glass up against the wall, open side down, and putting your ear up to the glass makes a reasonable stethoscope. Mark where the bees are loudest.
At this point you are not done as you still have a queen and a bunch of babies inside your wall, probably along with some honey, which will eventually rot and attract rats or more bees. So there is no non-destructive way to do the next step: you need to open the wall. There are probably some living bees still there, so again, wait until night to do this and they won't move much. You can suck the bees and honeycomb up with the shop vac. The honeycomb was unexpectedly flimsy and disappeared inside the shop vac like something of a magic trick.
I opened the wall before I'd sucked up all the bees, so could no longer use the "shop vac near the hole" approach. So I attached a six foot length of PVC pipe, about 3 inches in diameter, to the end of my shop vac with duct tape (showing my southern engineering skills!), which let me stand six feet away and suck up bees. I had to do this for a couple of hours before I got rid of all the bees. So my strong advice is to be patient and insure you have almost all the bees before opening the hole in the wall.
At this point, you can clean up the remnants of the honeycomb and any other crap you find in the wall, and you need someone to repair the hole in the wall.
This document exists because it is what I wish I had found before I dealt with the bees in my shed.