Here's a really cool idea for a different type of 'insect house' MB.
"The stag beetle, Britain's biggest native beetle, is a globally threatened species, protected under the Wildlife and Countryside Act of 1981, and listed as a priority species for the UK and London Biodiversity Action Plans. The number of stag beetles has been in decline since the 1940s.
The primary factor in their decline has been attributed to the loss of appropriate habitat – dead wood. The stag beetle requires dead wood to complete its lifecycle, as larvae feed on it for up to seven years before emerging briefly, usually in May, as mating adults."
stag beetle info - pdf
Bury Buckets 4 Beetles stagbeetlehelpline.co.uk