It is the little "wild" geranium known as 'Herb Robert'. It is a biennial that can spread quickly if allowed, but relatively harmless. I keep it out of my garden because it spreads too quickly. However it lives in the park across the street and stays under control there.

Thank you ontnative!
I don't think I would have ever figured that out.

I do like the looks of this one a lot.
After reading about "Stinky Bob" on Dave's Garden
it's alias I have just found out about - Thanks to your help -
I'll have to think about the 3 places
that I just put this into in my yard. LOL

It typically acts as an annual but is sometimes biennial. It seeds rampantly. In my state, this is a class B noxious weed!

I sure as heck wouldn't include it in my garden - it stinks, it's leggy, it spreads recklessly and aggressively and the flowers are minute compared to the amount of foliage that is produced - but to each his own :-)

I think it could be Geranium rubescens. G. robertianum has a white striped flower. rubescens is more pink