Definitely not stink bugs. They may be Hymenoptera (wasps, ants, bees), I don't think they are flies because the antennae are long. If you could see how many pairs of wings there are it would clinch between the two (one pair for flies and two pairs for Hymenoptera). I can't see the other distinguishing characteristics from the angle. I'm not sure that they're up to no good, some Hymenoptera can be beneficial while others like sawflies might be a problem. @GregC
probably can narrow it down.