One side milled MDF-boards are professional nesting boards and easy to handle. A simple system to open the nests, harvest the cocoons and rebuild the nesting blocks for the next season. You have to keep them always dry and protected from rain.
Each board has 10 nesting holes in 8 (Osmia bicornis), 9 mm (Osmia cornuta) or 6 mm (Megachile rotundata).
Size of plates: 16 cm x 16 cm x 1,6 cm