These specially drilled wooden tubes are the ideal for mason bees and leafcutter bees (Megachile spp) and other overwintering insects. The tubes come in a range of sizes from 5mm up to 12mm, the middle sizes 7mm to 10mm are best for solitary bees. They can be used to fill existing bee boxes, or to make your own simple bee nester.Solitary bees are gentle bees and are wonderful pollinators to increase vegetable, flower and fruit yields in your garden.From March to August these bee species will lay eggs in the tubes and create a series of cells from mud or leaf. The larvae will develop over the winter period in the tubes and will then emerge the following spring. Ensure that your own bee box is well-insulated or overwinter your full bee box in shed or garage. If left outside cover the full tubes with wire mesh to prevent predation from greedy woodpeckersPosition your bee box in a sunny position about 1 or 2 metres above ground, preferably amongst flowers/foliage, s