on my balcony

On the ground floor, earwigs, ladybirds and green lacewings will gather and use the loosely stacked natural materials as a hideaway during the daytime or as a place to hibernate over winter. The left and right compartments on the first floor offer ideal nesting habitats for small wild bees and digger wasps. In the middle, there is a winter home for butterflies. On the second floor, there are drilled pieces of wood for the nesting of larger wild bees, such as the Red Mason Bee. In the top floor “attic”, ladybirds and earwigs feel comfortable in amongst the natural materials.

http://www.neudorff.co.uk/natural-gardening/insect-hotel.html