one of my baby plants somehow got ants all inside of the cup, when i watered lastnight there were much more of them and they were pissed. I scooped out all that I could see and just tossed that soil and filled it up wiht more soil. I'm not sure if they're all gone... I'll find out next time I water. I was just wondering if ants can hurt a plants roots or not. I thought about it, and I'm not really sure. All their little tunnels could perhaps help get more air to the roots, but I'm not sure if the ants actually damage the roots at all like other pests...
If I remember correctly most ants have a symbiotic relationship with plants. However,I don't suggest keeping them around because it makes it harder for you to manage the plant. Crush some garlic up put it in a spray bottle with water. Shake well, and then spray that on your soil and your plant. The bugs will go away.