Why a Bug Hotel Earns Its Place

A well-made bug hotel is not a gimmick. In a British garden — especially a small one — it replaces some of the dead wood, crumbling mortar and hollow plant stems that used to be everywhere. Solitary bees such as the red mason bee and the leafcutter bee nest in hollow tubes, and they will readily use a hotel if the tubes are the right size. Ladybirds, lacewings, ground beetles and centipedes will move into the gaps and crevices around them. None of these creatures will sting you, bore into your shed or damage your plants. Between them they pollinate your fruit and flowers and eat aphids, slugs and other pests. You can build the whole thing in an afternoon from materials you almost certainly already have lying around.

Choosing the Site and Building the Frame

Site matters more than materials. Pick a sheltered spot facing south or south-east, where morning sun falls on the front. Solitary bees need warmth to get going, and a hotel in deep shade tends to stay empty. Avoid anywhere directly under a dripping gutter or a roof edge that funnels rain onto it, and keep clear of a wall that bakes all afternoon. Raise the structure off the ground on a couple of bricks or a paving slab so damp cannot wick upward.

For the frame itself, an old wooden pallet stood on its side works well, as does a wine crate, a stack of bricks with regular gaps left between them, or four offcuts of untreated timber screwed into a simple box with shelves. Use untreated timber only — tanalised, stained or varnished wood can leach chemicals into the nesting material. If you have no wood to hand, stacked bricks alone make a perfectly good beetle and frog shelter.

Filling It: Canes, Cones, Bricks and More

Variety is what makes a hotel work, but the materials must be packed tightly so nothing shifts. Loose fill rattles about in the wind and puts insects off.

• Hollow canes: bamboo, buddleia, elder or any hollow garden stems. Cut into 15cm lengths with an internal diameter of 4–10mm for solitary bees. Saw them cleanly so the ends are smooth. Bundle them into an old tin, a length of drainpipe or a section of the frame, with one end blocked — the bees need a sealed back wall. Leave the open end facing the sun.
• Pine cones: Wedge these into gaps between other materials. Lacewings and ladybirds tuck themselves between the scales over winter.
• Old bricks: Bricks with frogs, indentations or a few holes are ready-made beetle tunnels. Position them with the openings angled slightly downwards so rain cannot collect inside.
• Dead wood and bark: A log with the bark still on, drilled with 3–8mm holes to a depth of about 10cm, suits beetles and some solitary bees. Drill into the end grain, not straight through, and stack it low down.
• Leaf litter and straw: A small stuffed section at the base gives hedgehogs and beetles somewhere to shelter. Keep it dry and top it up if it slumps.

Matching Materials to Residents

Think of the hotel as a building with floors, and give each floor to the tenants who want it most. The top shelves should be the warmest and driest: that is where the bundled canes belong, and where solitary bees will do best. The middle holds pine cones, bark and thinner stems, which suit ladybirds and lacewings. The base takes the heavier, damper-tolerant fill — dead wood, bricks, leaf litter — for beetles, centipedes and the occasional overwintering frog.

Group similar materials together rather than mixing everything in one box. An insect looking for a 6mm tube will waste time and energy working through a jumble, and may simply give up and nest elsewhere. Keep the front of each section clear of obstruction so nothing has to squeeze past a protruding brick to reach its nest.

Mistakes That Empty a Bug Hotel

• Canes that are too wide. Anything over 10mm across is usually ignored by our native solitary bees — they cannot seal such a large opening.
• Jagged, splintered stems. Rough sawn ends tear delicate wings. Trim them neatly with sharp secateurs.
• Plastic string or netting left on bundles. It traps moisture and can entangle small insects.
• Sealed containers and plastic bottles. They sweat, and the condensation encourages mould that kills the larvae inside.
• Treated, painted or varnished timber. Untreated offcuts are always the better choice.
• Drilled holes that go right through. A tunnel open at both ends lets in draughts and predators, and no bee will use it.
• Facing full north, or sitting in a rain shadow. Constant damp is the quickest way to ruin a hotel.

Leave It Alone and Let It Work

This is the part most people find hardest. Once your hotel is built and sited, resist the urge to tidy it, move it, or clear it out. Leafcutter bees cap their nest tubes with neat circles of green leaf in midsummer; the larvae inside overwinter and emerge the following spring. Clear the hotel in March and you destroy an entire generation. Red mason bees work on a similar cycle, filling tubes in spring and spending the rest of the year as dormant larvae.

Give the structure a quick look in late September instead. Replace any material that has rotted through, top up the leaf litter, and check that the canes are still firmly bundled. If you want to add fresh nesting tubes, slot them in at the front rather than disturbing what is behind. Expect a quiet first year — a new hotel often takes a season to be discovered. Once the bees find it, they tend to come back to the same spot year after year, and the canes will slowly fill with sealed, mud-capped cells. That is your sign the build has worked, and the best thing you can do next is plant more flowers nearby and step back.