Question
I planted a young oak tree about 6 months ago (it's about 5 ft. tall and an inch wide now with new leaves coming out) and I noticed the other day a zillion ants had moved into the soil right down at the roots and there were winged ones climbing up the small trunk.  These are the tiny brown/red ants that have taken over my yard and bite or sting like hell when they get on you, I think bite. Won't these ants eventually kill the tree via the roots and any idea what kind of ant they are?
How can I defend the tree (first time I've actually planted anything that actually lived!

Answer
Ernie,

The ants won't hurt your tree. In fact, some ants actually protect trees from insects that feed on leaves. Depending on where you live these could be fire ants (based on your description of the sting). Take a look at this page http://www.livingwithbugs.com/fire_ant.html about fire ants. If you live within the area shown in the map (lower page) these could be fire ants. Fire ants won't hurt the tree but can be very dangerous to people.

Post a follow up if you have questions.

Jack DeAngelis, PhD
Extension Entomologist (ret.)
My website about home and garden pests: http://www.livingwithbugs.com