Here something I didn't know but know now
There are microscopic bugs called "oak mites" in, you guessed it, oak trees, and they'll give you a nasty rash.
I've cleared oak here now for 25 years now and never knew this, but the other day I was cleaning up some stray branches in the trees right around the house, piling them up to fork away... without my shirt on because it was a fantastic day.
Now I've got a bunch of bites on my belly, very rude.
At least they don't carry any diseases, and don't seem to stick around; seems like they just hit me when I was probably leaning on my branch pile to compress it to put more on it. Topical benadryl helps; the itch to me is more intense than poison oak but at least the rash is smaller.