The life cycle of this type of bee, which include, egg, larvae, pupa, and adult, lasts about seven weeks, although the developmental time may depend on temperature. In the spring (late April early May) the male and female will mate outside of the nest and together they will find a nesting site, the male will soon die after the female has found the nesting site. The female who is the main “carpenter” if you will, prefers a site that is an old nest which she will refurbish, rather than a new nest. If she does have to excavate a new nest she uses her strong jaws to create a clean cut round hole as the entrance to the nest. This hole is slightly less than 1/2-inch wide, approximately the diameter of her body. She bores into the wood perpendicular to the grain for one to two inches then makes a 90 degree angle turn and excavates along the wood grain for four to six inches to create a gallery (tunnel).
The Carpenter Bees prefer to create nests in softwood, but they also been known to create nests in hardwood as well. This type of bee can more easily tunnel through woods that are soft and that have a straight grain. Carpenter bees attack structural timbers and other wood products, including fence posts, utility poles, firewood, arbors, and lawn furniture. In buildings, carpenter bees nest in bare wood near roof eaves and gables, fascia boards, porch ceilings, decks, railings, siding, shingles, shutters, and other weathered wood. These bees avoid wood that is well painted or covered with bark.