Is the wood treated with any pesticides etc? Some wood, especially imported like wood pallets and other wood too, are treated either by heat (which is safer) or by insecticide to prevent exotic beetles from arriving with the wood.

It is possible they need to feed soon after a hibernation that is either disrupted or naturally timed.

I don't think your picture dipicts a carpenter bee. Females are huge and shiny black. Males are smaller and some mimic bumblebees. I am thinking wasp.....

Definitely doesn't look like wasps. Hard to be certain from the photo but they look "fuzzy".

Definitely bees.

I didn't question the carpenter bee ID at the time; if they had been called bumblebees, I wouldn't have questioned that either, given the blurry image.

I do think that they are carpenter bees. Picture isn't good enough to determine male and/or female.

Not blurry. Furry.

:P