In regards to Jane's comment on solitary Carpenter bees.... At least a few species of the genus Xylocapa have the habit of nesting together. Essig, in "Insects of Western North America" (now out of print) says that Xylocapa varipuncta makes burrows that are 5-12 inches long that may or may not be straight but which follow the grain of the wood. Several burrows may have a common entrance. In large numbers, carpenter bees can be damaging to building timbers and telephone poles. A very interesting critter, none the less. Dave Pehling WSU Coop. Extension [log in to unmask]