I have a tri-level stucco home. Small yellow jackets have found a small...
I have a tri-level stucco home. Small yellow jackets have found a small opening & have gone between the wall of my lower level floor. I have sprayed with bee, wasp & hornet spray in the opening at night, but they are still flying in & out. I was wondering if sealing the hole with caulk would be the way to kill off the nest. I would appreciate any ideas to help. Thank you!
I don't think sealing the hole will kill the yellow jackets, at least not immediately, as their nest is not likely built in a spot that is otherwise air-tight. It may trap them, causing them to die eventually, but It may just force them to explore another way to get outdoors. Very difficult to say without seeing the location of the nest.
Have you sprayed more than once? Often the majority of yellow jackets (or wasps, hornets, bees, etc.) will be killed by the initial spray, but oftentimes there are some survivors, necessitating a 2nd or 3rd spray. If the hive is a good distance from the hole in the wall it will be more difficult to thoroughly soak the hive as you would be able to do if it were out in the open, meaning you'd likely have to spray more than you would otherwise in order to kill them all.
Another consideration- are you certain they are yellow jackets? Your description of them as "small" yellow jackets, along with the fact they are nesting in the wall of your home makes me wonder if they aren't honeybees. If so this will complicate their removal for a number of reasons. First, honeybees are much more important as pollinators than yellow jackets and are also becoming increasingly endangered, meaning it would be more desirable to extract them without killing them than if they were yellow jackets. Secondly, if it's honeybees there are likely many more in the hive than if it were yellow jackets, just by the nature of how they habitate. And third, if it is honeybees, it will be necessary for you to have any honeycomb made inside the wall where they have formed the hive removed (which unfortunately is neither easy nor inexpensive), otherwise even if you remove the bees one way or another, you're very likely to find a new swarm will move into the same spot in the near future.
If you are certain that they are yellow jackets, I'd recommend spraying at least another time or two, making sure to use a spray that claims to shoot a stream 10 feet or longer. Following that I'd try to seal the opening and hope that cuts off any that remain and prevent future entry. If you are not completely sure if they are yellow jackets, leaving open the possibility that they are honeybees, I'd call your local extension office and have someone come look at them to verify which insect you are dealing with and recommend a course of action.