Quite ingenious, the cross-stacked reeds in the lower compartment, which bear witness to an extremely deep understanding of the breeding biology of solitary wasps and bees. Logically, a cavity from the opening has to be settled, in the case of abandoned beetle feeding programs in deadwood, a natural nesting sites, these openings are freely accessible. By contrast, the reeds come up against almost to the box sides. If the approaching mason bee or wasp not happen to have a chainsaw to hand her collection is likely to make it a bit difficult in the breeding tube.