I fed the birds a lot this winter and I'm going to see this same thing, I'm sure, when it starts to warm up. If you don't want them pull them early because the larger they get the harder they are to pull. I always let a few grow but they pull out easily at this stage.

Because you haven't had any responses, I thought I'd try to look up your plant in my weed book (Weeds of the Northern U.S. and Canada). Because you're in Georgia, maybe this is a species that wouldn't be covered but here are a couple of GUESSES: small snap dragon? blue-eyed mary? Have the plants flowered since you took the pictures? It looks like maybe there are some pinkish buds in the pictures but I can't be sure.

They do eventually flower, so you want to pull them up before they make lots and lots of little mare's tail seeds. They some right up, so it's not too bad.

Well, I ended up taking it to the extension office and they said it was kochia. It's an annual, so I'm not sure if I should bother to pull them up to prevent seeding. The extension office said they already dropped many seeds, so maybe I'll just let them die over the winter.