I don't mind them in balance with everything else. There are only two things I kill without mercy and those are lilly beetles, but I have stopped growing lillies, and vine weevil beetles as they can decimate a garden if left unchecked. I have had problems wth bad slug years where I have had so many that they actually killed a small shrub (pineapple broom) and I did use ferric sulphate that year. In my garden, even though it looks pretty much wild, it can't be left completely alone. If I did that it would ends up as a wilderness of docks, nettles and brambles and there would be less birds and insects and not more.