Thanks everyone. They always spray (fog) after dark. I just didn't know if it would have an impact on the bees. I could cover the hive at night with an old sheet.
Now, I'll have some questions about getting started with beekeeping. I ordered a couple books to read, and will soon be ordering the hive setup.
Where can I buy a bee package, that will ship through the mail?
I live in Illinois, but a little too far from Dadant to dirve to pick them up.