Bees are one of the most important and iconic pollinators, and they are in need of more habitat, food sources, and nesting locations. They are the pollinators of countless crops and native plant species, and carry out their job of spreading pollen far and wide. But with a changing climate, their future is a bit unsteady, and they are in need of assistance.
There are many ways to help pollinators, including planting pollinator friendly plants (see my post on Plants for Pollinators). Another great way to help native bee species is by building and providing a safe nesting space. A bee house is a human-made structure meant specifically for solitary bee species, mostly those who use tunnels to nest. This accounts for about 30% of all solitary bees, which includes hundreds of species in North America alone.
There are a few details that make some bee houses better for native bees than others. There is also some controversy over whether bees actually use bee houses and if they are beneficial. I am a firm believer in providing and letting the wildlife choose for themselves if it is valuable and useful to them. There are also many orchards that use bee houses as an advantage to pollinating their fruit crops and have had much success.
However, some characteristics of a bee house have proven better than others and will increase the chances of bees actually using it to nest. Most of these recommendations came from the Alberta Bee Council, but there are many species whose habitat overlaps with other places, so regardless of if you live in Alberta or not, this will still be relevant.
Tips for Making a Useful Bee House
The first is location, which is important for regulating the temperature on the inside of the house throughout the year, as well as making sure it is easy for the female bee to relocate and not have to fight through vegetation. It is recommended to hang bee houses at least three feet above the ground where nothing blocks the entrance, and facing South or East so that it is sheltered from direct afternoon sun.
Second, consider the design of the bee house so it allows a wide range of species to nest. If you are looking to purchase a bee house or build one like the DIY tutorial I have below, these tips will ensure it is a structure set up to be used by bees.
The house itself should be small in size to deter disease transfer, and be made of natural material like wood or cellulose fiber to ensure breathability.
Bee house tunnels should be around 6” in length and between 1mm-10mm (up to about ⅜ of an inch) in diameter. The deeper the chambers are, the better chance of a variety of species using them. Another source had recommended tunnel length be between 3-6”. The reason I mention this is because if you plan to drill holes in something like an old log, a regular drill bit is only about 3 ½” in length.
Space the tunnels apart if possible which will help the female bee find her tunnel.
Provide some kind of shelter from weather elements like a roof going over the entrance edge for the bee house, or remember to place the bee house somewhere protected like under a shed roof overhang.
DIY Bee House
This is a tutorial for making a beehouse yourself from upcycled materials, following the guidelines for a well designed bee house.
Before you start you will need:
Empty milk carton (1L or 2L) 36-48 sheets of recycled paper 2-3 sheets of newspaper Washi tape (or regular tape, however washi tape is made of natural fibers) A few sticks and/or thin scrap wood pieces cut to 6 1/2″ 3-4 small elastics or a small length of string
Optional Roof: 2 pieces of 1×6” wood cut to 9” each (for creating a roof), nails, hammer
A ruler Full size pencil crayon Scissors Stapler String or hooks for hanging
This bee house uses rolled paper tubes as the nesting tunnels, which is quite strong when tightly rolled and makes maintenance the following year easy (simply switching out the tubes for new ones after cocoons have hatched, which limits disease transfer).
Preparing the Carton
First, take your milk carton and cut the folded end off. After removing the folded end, the Caron should measure roughly 7 ½” long.
Cut a half-inch slit down each corner edge, and fold half an inch of the open carton end into the inside. (Cutting the edges slightly makes the folding easier). Staple the folded edge in place. The carton should now measure 7” in length.
If you are attaching a wooden roof to your carton, nail the two wooden slabs together at the small edges, forming a right angled “roof”. I have cut both edges to a 45 degree angle, however if you don’t have the right tools, you can skip that step.
Set the carton into the wooden roof, with an inch of overhang on either side. Using a manual staple gun good for use on wood, staple the carton to the roof pieces from the inside of the carton. You probably won’t be able to reach all the way to the back of the carton and that’s okay, just put a few staples on each side at the front and half way back until it seems secure.
Fold the newspaper to make 6 ½” lengths, and lightly roll to make it easier to place in the carton. The newspaper provides a bit of insulation for the nesting tunnels. You could also use paper towels here instead.
Rolling the Tubes
Rip the paper a few sheets at a time using the ruler. You will be ripping (or cutting) the sheets down to 6 ½” so it will fit into the carton nicely once rolled. Each sheet before rolling should measure 11×6 ½”.
Take the short end, and place the pencil on the paper along the edge, tightly roll the paper around the pencil until you end up with a paper tube. A pencil is perfect because it measures about ¼”, and will end up with a 5/16” size tunnel.
Once your tunnel is rolled, place a small piece of washi tape in the center to hold it, remove the pencil, and place a longer piece of washi tape at one end.
At the other non-taped end, pinch it flat and place a small piece of tape over it. The reason for pinching one end is to make sure predators can not sneak in through the back of the tunnel.
Roll about 36-48 tubes total, and bundle them gently in sets of 8-12 with a small elastic or string.
Once all your tunnels are rolled, place the bundles inside the newspaper wrapped carton. You’ll notice there are a few spaces between the bundles, especially if you chose to only roll 36 tunnels. It is good to have other materials in between tunnels to aid the female bees in finding the right tunnel. Use cut sticks and small scraps of untreated wood to fill the space in between the tunnels until the tunnels do not move around in the carton. We want them to stay secure in the carton held by tension to make sure they can’t fall out or be removed easily.
Once the assembly is finished, you will need a fastener to hang it outdoors. You can use hooks if you have a roof on your carton, or twine tied around the carton a few times.
This is a great way to upcycle some recyclable materials and give them a second use. This little bee house also goes well alongside a pollinator friendly garden. Providing nearby building materials for bees such as dirt/clay/mud or leaves can also increase the use of the bee house. Mason bees are an example of a bee species that builds tunnel nests using mud (like a mason). They are pollinators of fruit trees, so if you have orchards nearby or blooming fruit trees in your yard, this type of bee house will be a perfect addition to your outdoor space.