I have just started growing giant sunflowers (10 ft.). I started by seed, and they are about 1 and a half to 2 ft. high right now. i am growing them in large pots on my patio. I have noticed that tiny ants are digging and going down the stem into the dirt. Why, and is this a bad thing? What should I do?

Ants generally don't harm plants. If they are nesting in the pot though, you might have an invasion on your hands in a week or two. I'd put a little bit of diatomaceous earth powder around the bases of the plants to discourage them. They will pick up and move on.

You can get d.e. in a bag at any big box store. It's completely inert, but is sort of like tiny pieces of broken glass to the ants and if they walk through or over it they dessicate and die. Be careful not to breathe the dust as it can make you cough.

If these were planted in the ground I would not be concerned in the least, I see ants on/around/digging near my outdoor sunflowers all the time and they do no harm. But being as these are in containers I'm not 100% certain, as container gardening in not something I do much of.