Not trying to scare anyone, but we should start to be on the lookout for Small Hive Beetles, just in case. You should be particularly aware the second you first open the cover on your hive, as the beetles will quickly scurry for cover to try and hide. They do not like light.
I have found a very good, informative, but short (only 2 pages) data sheet on SHB. It originates in Italy, but the biological information is good without being overwhelming;