Houses are the easy part
A bee house or insect hotel is a good conversation starter and a small way to help some native bees. It is also easy to get wrong. Cheap decorative hotels filled with pinecones and tiny drilled holes can attract few insects, or the wrong ones, and some designs can build up parasites and mold. Butterfly houses are mostly decorative, because butterflies rarely nest in boxes. What reliably helps pollinators is food, host plants and shelter, and a few houses can sit on top of that foundation.
Which bees use houses?
Most native bees in North America nest in the ground, in burrows in bare or sparsely vegetated soil. A smaller group, including mason bees, leafcutter bees and some small carpenter bees, nests in hollow stems or holes in wood. Those are the bees that may use a bee house. Honey bees, bumble bees and many solitary species will not.
Native bees are mostly gentle. Solitary bees do not have colonies or honey to defend, and the males cannot sting. They will not swarm your yard. Our native bees guide and mason bee house basics explain more.
Designs that make sense
Extension services such as Utah State University commonly describe bee nesting blocks and tubes that follow a few principles:
- Holes of the right size. Different species use different diameters. A mix of sizes, from about 1/8 to 3/8 inch, is common, and one popular size for orchard mason bees is about 5/16 inch.
- Closed back ends. Tunnels should be blocked at the rear, with a solid back and a hole depth of roughly 3 to 6 inches, so bees are not exposed on both ends.
- Smooth, clean interior. Splinters can damage wings and rough tunnels invite parasites.
- Removable or replaceable tubes. You should be able to swap out paper or cardboard tubes each year, or clean the tunnels, so mold, mites and parasites do not build up.
- Dry and sheltered. Eaves or a back panel keep rain off.
A deeper hole in a solid block of untreated wood, drilled without going all the way through, is a good do-it-yourself option. Avoid bundles of bamboo with wide, open ends, glued or sealed tubes that cannot be opened and cleaned, and treated wood.
Where to put a bee house
- Face the morning sun. A southeast-facing spot warms bees early. In the hot Plains summer, provide some afternoon shade.
- Height. A common recommendation is roughly 3 to 6 feet off the ground, firmly attached so it does not sway in wind.
- Near flowers and mud. Mason bees seal their cells with mud, so a patch of damp, clay-rich soil nearby helps them.
- Out of the rain and away from sprinklers. Moisture breeds mold.
Yearly maintenance
Bee houses are not set and forget. Replace paper tubes annually, or clean the nesting channels and the box when the cocoons are no longer in them, following the instructions for your type of house. If you leave the same tunnels in place year after year, parasites can build up. For mason bees, there are well-known practices for harvesting cocoons, storing them and releasing them in spring, which we outline in the mason bee guide.
Butterfly houses
A butterfly house is typically a narrow wooden box with vertical slots. The idea is that butterflies will shelter inside. In practice, few butterflies use them, though a few species that overwinter as adults, such as mourning cloaks and question marks, may seek shelter in woodpiles, bark crevices and leaf litter. If you like the look, there is no harm in having one, but do not expect much, and do not use it in place of plants. Our butterfly houses guide gives the details.
What actually helps butterflies:
- Host plants for caterpillars. Monarchs need milkweed. Swallowtails use plants in the carrot and citrus families, and painted ladies use thistles and mallows. Native plants support more species than ornamental ones.
- Nectar plants. Choose a mix that blooms from spring to frost.
- Sun and shelter. Butterflies bask in sunny spots out of the wind.
- Puddling spots. A shallow dish of damp sand or mud gives males minerals.
- No pesticides. Insecticides, including some garden products labeled as safe, can kill caterpillars.
Leave some mess
Many native bees and other beneficial insects overwinter in hollow stems, in leaf litter or in the soil. A tidy yard is a poor habitat. Leave some stems standing through winter, let some leaves stay under shrubs, and keep a patch of bare, well-drained soil in a sunny spot.
Common mistakes
- Buying a decorative hotel with no cleanable tubes.
- Placing it in shade or a cold, damp spot.
- Forgetting yearly maintenance.
- Skipping the flowers.
- Using pesticides near the house.
Frequently asked questions
Do bee houses really help bees?
They can help cavity-nesting native bees such as mason bees if they are well designed and maintained. Most native bees nest in the ground and will not use them.
Will a bee house attract wasps?
Some insect hotels attract small solitary wasps, which are beneficial predators of pest insects and rarely sting.
How often should I clean a bee house?
At least yearly. Replace paper tubes or clean removable ones, following the guide for your type of house.
Do butterfly houses work?
Rarely. Host plants, nectar flowers and shelter such as leaf litter help butterflies more.
Where should I put a bee house?
On a stable post or wall, about 3 to 6 feet high, facing the morning sun, out of the rain and near flowers and mud.
