They are Asian Beetles. We have had a couple of very bad years in WI. They invade everywhere. We had the RV sitting unheated in freezing temps last fall. We left for Arizona in December, and as soon as we hit warm weather, the darned things came out in huge numbers. We used our Dyson to suck them up, then we would dump them into a bag and kill them. We did this for 60 days, killing between 30 and 80 a day before they finally were eradicated. Please don't release them; destroy them. It seems they crawl into crevices to hibernate and then come out when the weather warms up.
We accumulated them in WI and did not want to introduce them to the RV park in AZ.