What To Know About Insect Houses

As a kid, watching insects in my backyard helped me develop a deep curiosity and appreciation for the intricacies of nature. Today, I still love being a voyeur in their world.

But the helpful insects in our yards serve more important roles than entertainment. They pollinate our gardens, keep pest insect populations in check and feed birds and other wildlife. The more diverse the insect base you can attract, the better.

Installing insect houses is one way to increase your yard’s biodiversity while bolstering shrinking insect habitats.

“As urbanization of native areas occurs, insects often lose prime habitat,” says Francisco Garcia Bulle Bueno, Ph.D., target species manager at the Butterfly Pavilion. “Therefore, providing insects with houses is a great way to positively support them.”

Unfortunately, these little hotels aren’t always successful, and some aren’t any more than a marketing ploy. So here’s how to choose the right insect homes and make them a success in your yard, with advice from Garcia Bulle Bueno and experts at Xerces Society for Invertebrate Conservation and the National Wildlife Federation.

About the Experts

Mary Phillips leads the National Wildlife Federation‘s Garden for Wildlife and Certified Wildlife Habitat programs. As an ambassador for nature, she keeps habitat gardening programs flourishing with sustainable practices and ever-evolving scientific knowledge.

Francisco Garcia Bulle Bueno, Ph.D., is the target species manager at Butterfly Pavilion in Westminster, Colorado. Butterfly Pavilion is the first standalone non-profit insect zoo in the United States.

Jennifer Hopwood is a senior pollinator conservation specialist with the Xerces Society for Invertebrate Conservation, where she builds training programs for beneficial insect management and landscape restoration.

What Is an Insect House?

Insect houses — aka butterfly houses or bug, bee or insect hotels — are fabricated structures that provide shelter, overwintering and nesting sites for beneficial insects. Generally wooden, they’re typically installed in gardens and yards. They include compartments made from natural materials like bamboo tubes, pine cones and straw.

How to use insect houses effectively

Each insect species has particular needs, but here are a few universal tips to keep in mind:

• Spread out houses across your landscape to limit parasites and disease.
• Provide adequate space between nesting materials and compartments to avoid overcrowding.
• Steer clear of glued materials, which can be harmful. Also avoid non-natural materials like metal or plastic, which aren’t breathable and can facilitate mold and fungus.
• Place houses close to flowers, where they’re protected from the elements but have adequate airflow to prevent fungi and disease.
• Plant a diversity of native plants in your yard.
• Don’t use pesticides in your yard.
• Place houses three to six feet off the ground and away from birdfeeders and ponds to protect insects from predators.
• Face houses south or southeast for morning sunlight and afternoon shade.

What To Know About Bee Houses

Bee houses are artificial nests for solitary species like mason and leafcutter bees. They’re typically wooden boxes with pre-drilled holes or tube inserts. In the fall, bees lay their eggs in the holes, stockpile pollen for the larvae to eat, then seal the tubes with mud or leaves.

These houses mimic the conditions required for bees nesting in above-ground tunnels, according to Jennifer Hopwood, a senior pollinator conservation specialist with the Xerces Society for Invertebrate Conservation.

“In the wild, tunnel-nesting bees will seek out hollow or pithy stems, beetle burrows in wood or other existing tunnel cavities,” she says.

How to use bee houses effectively

Bee houses tend to support introduced species, rather than native ones in need of conservation, Hopwood says. That’s a concern. Plus, they can increase rates of parasitism and disease.

To make bee houses as safe and welcoming as possible to native species, do the following:

• Keep bee hotels small, with just four to six entrances.
• Replace internal materials every growing season, and clean houses with a brush and water.
• Install in early spring before bees emerge from cocoons and become active.
• Use tubes or holes six inches long, with diameters between 0.125 and 0.375 inches.

“Many manufacturers use bamboo that is not the correct size for native bees,” says Garcia Bulle Bueno. “If the opening for the bees is too large, they will not use it. Instead, you will most likely have wasps or other non-target species nesting in the house.”

Do bee houses work?

Yes, when installed correctly. “Many solitary bee species cannot create these holes themselves, and natural nesting sites aren’t always available, so bees will use these houses as replacements,” says Mary Phillips, who leads the National Wildlife Federation‘s Garden for Wildlife and Certified Wildlife Habitat programs.

What To Know About Butterfly Houses

Butterfly houses are generally wooden boxes with narrow slits, giving butterflies a place to hibernate or just hide out during a storm. Target species are those that overwinter as adults (vs. as eggs, larvae or pupae), like mourning cloaks and question marks.

Do butterfly houses work?

Usually not.

“There isn’t evidence that butterflies use these structures,” says Hopwood. “Additionally, butterfly houses may unintentionally increase predator pressure on butterfly survival or populations.” This happens because the houses also attract ants, spiders and wasps that prey on caterpillars and butterflies.

How to use butterfly houses effectively

Rather than installing a house to attract and support butterflies, Phillips says it’s better to stock a pollinator garden with native plants, including host plants and nectar sources. “Add a flat rock to give butterflies a place to warm up in the sun, and a puddling spot to provide them with hydration and minerals,” she says.

But if you still want to try one, make sure to clean it regularly to get rid of unwanted insects and debris, says Garcia Bulle Bueno.

What To Know About Insect Hotels

You can buy or make lots of shelters to support other bug species like solitary wasps, lacewings, lady beetles and spiders. These hotels come in various shapes and sizes, and sometimes also support bees. Ideally, they include a roof or overhang. They’re made from natural materials like recycled wood, straw, pieces of terracotta, cardboard, stones and bark.

Do insect hotels work?

Yes, when done correctly.

“Having a bug hotel in the landscape can provide valuable nesting and hibernation sites for beneficial insects, therefore contributing to increased biodiversity and pollination,” says Phillips.

Insect hotels are also especially good for collecting citizen science data about insect populations through apps like iNaturalist, Phillips says.

How to use insect hotels effectively

“Bug hotels can be successful in attracting different species if they’re placed in a proper location,” says Phillips. To find the best places, follow the general guidelines above and research your local native insects’ needs. Then tailor the hotel accordingly.