Uhoh! Run for your life. Those are the brand new nymphs of the dreaded Brown Marmorated Stinkbug. Search long and hard for any others and dispose of in a jar of soapy water.
These have become THE most common pest in recent years. If I were you, I'd become very familiar with their appearance in all stages of life. They look different every time they shed their exoskeleton. You don't want to mistake one of the beneficials by mistake.
Getting rid of the nymphs, before they have a change to develop wings, is important.
I didn't make it thru my instars in time. Good 'un rhizo. Sadly we have far fewer bugs to familarize ourselves with, but you just know that's a bad one.
Thanks much! They're outta here.