09/03/2026
Those holes in your fence aren't damage, they're a nursery
Neat round holes appearing in old fence posts, bee hotels or soft dead wood aren't rot or woodworm. They're often the work of red mason bees, one of Britain's most common and important solitary bees.
The red mason bee (Osmia bicornis) doesn't chew fresh tunnels into solid timber the way some overseas bees do. She finds existing hollow stems, old beetle holes or bee-hotel tubes, then works methodically: brings in mud to build a wall, packs in a ball of pollen and nectar, lays a single egg on top, seals the chamber, and repeats along the tunnel until it's full.
The dust and debris you sometimes see nearby isn't decay, it's leftover mud and nest-building material.
Males patrol close to the nest site and can look bothersome, but they have no sting at all. All presence, no threat.
Meanwhile, red mason bees are exceptional pollinators. Gentler and less fussy than honeybees about cool or damp weather, a single female can do the pollination work of dozens of honeybees across fruit trees, soft fruit and early spring blossom. Bumblebees add another layer many gardeners don't know about: buzz pollination, where rapid muscle vibrations release pollen from flowers like tomatoes that honeybees simply can't trigger in the same way.
Three things worth doing:
- Leave old hollow stems, bee hotels and soft dead wood in place rather than tidying them away over winter
- Site a bee hotel in full morning sun, sheltered from driving rain
- Don't spray anything near nest holes. Lose the pollinator, lose the fruit set
A tiny brain, weeks of careful work, and the one hovering near your face isn't going to do a thing.