Yellow jacket time of year
I was reminded rather painfully yesterday that this is the time of year when yellow jacket nest building is going on. When digging, be alert for signs of yellow jackets flying around the ground and especially for any visible hole with activity. If you are not digging or disturbing the ground, I don't think they bother with you unless you are right at the hole, but I am no expert.
If you dig near a nest (which is in the ground), they will sting you. My experience (and this is my second episode in a few years) is that after the first one stings you, others will follow - literally! Yesterday they followed me quite a ways, not a swarm of them, but enough to keep stinging me as I went. I got 8 stings in all! I did manage to kill a few of them on the way ....
So, be careful! They especially like to build nests where there are pieces of old wood/logs, but that is not a sure thing.