One of our 7 Kestrel nestboxes is installed in tree at a home adjacent to a wildnerness area in the hills of Los Angles and was occupied by a Western Screech Owl. Not the expected outcome from the project, and both the homeowner and my husband and I were **thrilled** by the spunky, photogenic owl.
Then, the homeowner reported an invasion of bees and the absence of the owl, much to the disappointment of all.
Question for all of you, as this was the first time we've had this issue.
-- What can we do to prevent bees from taking over a nest box and that also do not discourage Kestrel nesting? (On the web we've read of coating the inside of the box with Pam or odorless soap as bees do not like slippery surfaces. We also read of coating the interior ceiling of the box with aluminum foil to dissuade bees.)
--On the web we have also seen mentions of using pepperment or cinnamon essencial oil to repel the stinging insects, or using mothballs. Is it known if these scents also discourage Kestrels from using the nestboxes?
-- Once there are bees, wasps, hornets, or yellow jackets, what are our options? It will be kinda expensive if we need to hire a professional to get rid of them each time. Should the nestbox be destroyed since there could be a lingering scent that continues to attract the insects?
--Is there anything about having an owl occupy that box that makes it somewhat more appealing for bees? Trolling on the internet, we found a number of references to bee problems with owl nesting boxes and we find it curious that of our 7 boxes the only one with a bee problem is the one that was used by an owl.
We welcome any and all information you could provide about avoiding and managing bee infestations.
Thanks SO MUCH.
I'll take a stab at answering your questions. I maintain anywhere between 3-7 bee hives during the year.
1) The size and shape of a kestrel box (or owl box) is a little bit smaller than ideal for a swarm of bees. That being said, they are opportuinistic and will adapt to what they have. I personally wouldn't suggest coating the inside of the box with anything. I'm not sure it will work, and it's probably a lot of effort for you. I can't speak to the other effects it might have on your target wildlife.
Bees tend to swarm in the early spring, about the time that the birds are also looking for a nest. Physically stopping up the entrance isn't going to get you the desired effect, either.
2) Unknown to me if essential oils will deter bees or stinging insects. I don't think the essential oils will last long enough to be effective in your application, however. I personally wouldn't use moth balls.
3) If you have honey bees, there are many, many local beekeepers who would be happy to come re-home the hive, for free. Get plugged in with a local beekeepers club or association. There is usually a phone list for people who want someone to come rescue a swarm or remove a hive. Given that a next box is very accessible, most beekeepers would be happy to come take them off your hands. They should be able to clean up the box well enough that it is not an attractant for future swarms. You might even get some honey out of the deal. I wouldn't destroy the box until you have a recurring problem.
I don't think you'll have problems with other insects. Nest boxes are not ideal for bumble bees, yellow jackets build their nests in the ground, and paper wasps prefer to build their nests in trees.
4) No correlation between the owl and bees. The bees were looking for a home, and the nest box they found fit the criteria for size, shape, height, etc.
I really think this is a one-off problem. Given that you have seven nestboxes, it was statistically likely that you would eventually run into honeybees.
I wouldn't coat inside with anything. I would especially not use mothballs which are toxic to everything.