Manmade bee nest boxes
Our bee houses
This photo was taken soon after we installed some of these bee houses, so the wood is still new-looking. The wood eventually weathers, though, so they'll blend in pretty well.
We've tried a variety of styles, just to see how each type worked.
Notice that these houses are about 5 inches deep. They need to be this deep since the depth affects the proportion of males and females produced. We try to maximize the number of females since those are the ones that do the pollination work!
Provisioning the nest
We've been fascinated watching bees lay their eggs in these bee houses, both homemade and commercial versions, and we've learned a lot by watching them.
We've seen quite a variety of bees, each with their own ways of provisioning the egg cells.
Some birds found some tasty morsels in this bee house made with softer wood
As much as we've enjoyed these houses, I'm beginning to think that, at least in our suburban yard (as opposed to a farm or orchard needing heavy-duty pollination), we should focus more on providing as much natural nesting habitat as possible.
This eliminates the need to keep the bee houses clean. It also avoids concentrating all the larvae in one place, which can make them sitting ducks for predators, such as birds or chipmunks.
A downy woodpecker looking for a meal
I suspect our yard probably has enough places for them to nest even without manmade houses.
We still use the houses we have, since certain ones might provide good nesting places for certain kinds of bees (and it's still interesting to watch them).
John just drilled lots of different size holes (between 2 mm and 10 mm) into this assembled hunk of wood, making sure he bought only NON-pressure-treated wood. (Pressure-treated wood is full of toxic chemicals.)
He nailed three 2x4s together and then drilled the holes almost, not completely, all the way through. It's important to have a good drill bit so the insides of the holes are smooth.
He added a roof to keep rain out.
Many different types of bees and wasps use these holes, each choosing the size hole they prefer.
Entering John's nest box
It's been pretty successful, though it can't be cleaned out as easily as commercial ones can be.
It's true that nest areas in the wild aren't cleaned out either, but we're trying to provide optimal conditions.
Also, I wouldn't think bees would be nesting in such density in a natural setting or even reusing nest sites.
We tied these elderberry stems together for nesting space for bees. I imagine there are other stems that are naturally hollow, but we happened to have some elderberry prunings.
We cut them above a plant node so there would be a natural end at the back so they weren't just a hollow pipe.
Purchased bee houses
I like this type of bee house. It's easy to clean because it disassembles, and it has four different hole sizes to accommodate different types of bees.
Some of these larvae (maybe even most?) overwinter as larvae and leave the next spring.
I haven't kept track enough to know how many batches of young are produced each season.
This is what's going on inside those houses. Different types of bees and wasps make different types of cells.
These are solitary bees as opposed to social bees like bumble bees and honey bees. They fill up a channel with their eggs, provisioning each cell with what their larvae need. Once the channel is filled, that's the end of their parenting responsibility.
They don't stick around to defend a hive, which is the reason these native solitary bees aren't aggressive.
Together, but solitary
Many individuals may nest "together" in one area—in this case, this bee house— which shows four different bees and wasps using it.
BUT they're aren't organized into a social unit with different roles, such as a honey bee hive or a bumble bee colony would have. They just happen to be nesting in proximity to one another.
And even though bumble bees are nesting in a colony, we have found them to be pretty docile and very easy to coexist with.
This is the newest style of beehouse we've bought. It's plastic, which should make it much easier to clean. I'll have to observe it for a while to see if it's as appealing to bees to nest in this plastic.
Less successful kinds
A bumble bee house
When we first became interested in bumble bees, we bought this somewhat pricey bumble bee house. Unlike solitary bees, bumble bees are social and nest in a colony, generally in the ground. It was a challenge to provide the right conditions for them to use this house.
It can be done I'm told, but it apparently involves capturing a queen and putting her in the house to get her interested. I'd rather provide the bare ground she's looking for, so we haven't pursued using this.
But I would have loved to see how a social bee colony worked.
In the past, I favored this type because it's so easy to clean and to get ready for the next year. I simply removed the straws and put the occupied ones in another container until they emerged, then replaced the house with clean straws.
Of course, one downside was that the straws are pretty pricey considering they're single-use.
I did try to buy beverage-style paper straws, but they're hard to find in any size. The size of the hole didn't really matter since, unlike a farmer, we're not focusing on orchard mason bees, just any native bees, some of which are pretty small.
But they just don't seem to make paper straws anymore. In fact, the teen at the register of a restaurant supply store didn't believe there could even be such a thing—"But paper would get wet!" she told me, thinking I was a little confused. Clearly, she couldn't conceive of a time before plastic was invented.
Anyway, I say that I used to prefer these until I spoke with an entomologist who considered these to be a "sink" rather than a "source" for bees in my yard. (In other words, they wouldn't necessarily be able to complete their life cycle, and thus the eggs would be wasted.)
Now for the life of me I can't remember her reason, just that whatever her reason, it made sense to me at the time, so maybe this type isn't the best choice.