¥ Interlocking tiles have around ten hollow chambers. As the cavities in the tile are open all the way through, the tile should be sealed at one end with concrete or plaster. The tiles are stacked or stored upright in the wild bee house.
¥ Some species of wild bee do not nest in existing cavities; they prefer to create passages by gnawing and specialise in pithy plant stems. In the natural world, only stems which are vertical or diagonal, and which release pith when force is applied, are colonised, such as blackberry stems. These will be placed standing upright at the external wall.
• A site which is protected from the weather to an extent is required for cardboard tubes. Cardboard tubes are practical as they are already the right length, and do not need to be cut beforehand. They can be used immediately. As the tubes are open on both sides, one side should be placed against a smooth surface, or sealed with plaster, wax or untreated cotton, and integrated into the wild bee house.