Ants and my Japanese Maple

Over Labor Day weekend I bought a Japanese Maple at Blue Mount. Got home, dug the hole, started to pull it out of its pot and noticed TONS of tiny ants in the pot around the root ball. Planted it anyway, and they're still crawling all around the tree. I don't think they've wandered too far; haven't seen them in the house.

I thought about calling Blue Mount asking for advice, but based on a few experiences there I have less than 100% confidence in their advice. So I thought I'd see if anyone here had any comments. I don't care so much about ants, as long as they don't pose any threat to my tree. So... my questions are:

1. Do they pose a threat?
2. Will they die off this winter?
3. Should I do something to try to get rid of them, either to save the tree or anything else previously planted in my yard?

Thanks!

 

If the nest is in the roots, they may be eating them (the roots). If you're watering the new tree liberally (as you should water a new tree), they might move to someplace drier. They may have moved into the root ball originally to get up out of too wet ground. keep an eye on it and use insecticide if they're still tehre after a few weeks (I rarely advocate insecticide except for right on ants).