I don't know if they do anything beneficial. But I doubt that they'll hurt anything. At least you don't live where there are fire ants. I've seen them cut up and carry plants away in a day!

George
Tahlequah, OK (Where, thankfully, we don't have fire ants!)

I'm in MD as well and sometimes my blossoms are crawling with dozens of ants in the morning. They are too small to pollinate squash flowers. All they are after is the nectar in the blossoms, they don't harm anything.

I also do not have the destructive kind of ants.

I actually have a small hill in my zuc/tomato patch. All they do is wander over everything, and herd aphids on my sunflowers, which are so tough nothing will kill them, so I let them do their thing (I have to remember to plant a sunflower near the hill every year for them, though. Don't want them herding aphids onto the tomatoes!