Recently, I've noticed that ants have been forming hills in my garden. They're not in the middle of everything, and they aren't all over the place. I believe they are typical black garden ants (Lasius Niger). I also think I saw some aphids. I've been keeping an eye on some nearby plants, but no ants or aphids on them. I believe them to be the cause of the demise of some snowdrops and species tulips. Am I better off without them? Can I still plant stuff near or around the hills? Or will their tunneling interfere with root growth?

Thanks in advance, Brandon.