Within the United States carpenter bees are categorized in two genera – large carpenter bees (Xylocopa) and small carpenter bees (Ceratina). Xylocopa is the group of carpenter bees most likely to make their presence and associated damage known to property owners. The most obvious characteristic used to separate these two genera is size – Ceratina are less than 8 mm long, while Xylocopa are anywhere from 12-25 mm long. Xylocopa are similar in size and appearance to bumble bees. The insects can be black, greenish black, metallic blue, or purplish blue in color. Males may feature yellow sections of the face. Both males and females have yellowish hairs on the legs, thorax, and abdomen, but these hairs aren’t as vibrant or as numerous as they are on bumble bees.