Bee hotel problems: troubleshooting the six most common complaints

At a glance: the six problems and their usual cause

Problem one: no bees are moving in

This is the most common complaint and rarely means bees are absent from the area. Check three things in order: position (south to south-east facing, 1–1.5m high, firmly fixed, sheltered from wind and rain — see our positioning guide), tunnel diameter (a hotel drilled to one size only suits one or two species at most), and timing (a hotel hung after the March mason bee emergence has to wait for the next wave, or for leafcutters in summer). Most hotels that will ever be found are found within their first two seasons.

Problem two: mould at the tunnel entrances

Mould is a moisture problem, not a hygiene one — pollen loaves and mud caps that stay wet grow fungus, which can kill developing larvae. The two usual causes are a roof that doesn't overhang the nesting face enough and a north-facing or overly exposed position that never fully dries out between showers. The remedy is repositioning in late winter, not cleaning tunnels mid-season, which risks damaging active nests.

Problem three: parasitic wasps

Small parasitic wasps target solitary bee larvae by laying their own eggs inside occupied cells, and open or through-drilled tunnels make this far easier by giving access from behind. A solid rear panel closing every tunnel is the single most effective structural defence. Some background level of parasitism is a normal part of the ecosystem and not a sign of a failing hotel — it becomes a real problem mainly where tunnels are unsealed at the back or the same hotel has been heavily used for many years without any turnover.

Problem four: woodpeckers

Great spotted woodpeckers and other birds will peck out capped tunnels over winter, drawn by the protein-rich larvae inside. It is more likely where a hotel is mounted somewhere with an easy perch directly in front and the capped entrances are clearly visible and exposed. Fitting fine mesh a few centimetres clear of the nesting face over winter protects tunnels while still allowing bees to emerge freely in spring; remove or loosen it before the season starts.

Problem five: ants

Ants investigating a bee hotel are usually following a food source nearby — spilled bird seed, aphid honeydew on an adjacent plant — or exploiting a support that gives them an easy climbing route up. They rarely breach properly capped, mud- or leaf-sealed tunnels, but persistent activity is worth tracing back to its source in the garden rather than treating the hotel itself.

Problem six: tunnels were never sealed, or the hotel has fallen down

Two separate build-quality issues get grouped together here because both trace back to cut corners. Tunnels drilled straight through a block with no backing panel are corridors, not nests, and let damp and parasites in from both ends. Separately, a hotel that has come off the wall or post almost always failed at the fixing — a single screw or a bracket not rated for the combined weight of wet timber and occupied, mud-filled tunnels. Refix with at least two solid points into masonry, a fence post or a structural stud, and check it periodically as described in our care guide.

Design choices that prevent most of this from happening

• Solid rear panel on every tunnel, closing off the main route parasitic wasps use to reach brood.
• Overhanging roof that genuinely projects past the nesting face, not a flat lid.
• Thick, untreated timber that buffers temperature and resists rot without chemical treatment.
• Rigid mount rated for the hotel's full loaded weight, fixed at more than one point.
• A genuine size range across tunnels, so more than one or two species have a realistic chance of using it.

When to stop troubleshooting and start again elsewhere

If a hotel is well built, well positioned, and has still had two full seasons with no activity at all, the most likely explanation is a genuine local shortage of tube-nesting species rather than anything wrong with the hotel — moving it to a spot with more flowers and bare soil nearby is worth trying before assuming failure. For everything else on this page, the fix is almost always a specific, identifiable cause rather than bad luck.