Similar in size and appearance to bumble bees (Bombus sp., Apidae), the bee shown here is actually an eastern carpenter bee (Xylocopa virginica, Apidae). You can tell them apart by looking at the top of their abdomens. Bumble bees have fairly hairy abdomens that are usually colored black and yellow, while large carpenter bees (Xylocopa sp.) have upper abdomen surfaces that are mostly black and bare (Triplehorn and Johnson 2005). You can see that the abdomen on the bee above is shiny and mostly hairless.
There’s another difference regarding their nesting sites. Bumble bees usually nest in the ground, while large carpenter bees excavate nests in solid wood (Triplehorn and Johnson 2005). Large carpenter bees are sometimes considered pests since they’re capable of weakening bare structural timbers.
I found quite a few of these bees feeding on the nectar of common marigolds (Tagetes sp., Asteraceae) in a southeast Michigan greenhouse. Based on the very large eyes and yellow facial marking, the bee in the second photo appears to be a male.
Triplehorn, C.A. and N.F. Johnson. 2005. Borror and DeLong’s Introduction to the Study of Insects. Seventh Edition. Thomson Brooks/Cole, Belmont, CA.