It's a problem isn't it Steve? I hate chemicals too, and feel awful resorting to Weedol lawn weeder, Pathclear and Roundup (which contains glyphosate, a chemical with a bit of doubt about its safety. However, there's been a 'stay of execution' on banning it for 18 months until further research is undertaken. Possible link to cancer)

We had an ants' nest on our front doorstep. Husband wanted to paint the step a cheerful red, but the ants kept making little piles of sand. I got an ant-killer powder, but watching the little creatures busily marching about, I just hadn't the heart to murder them. We gently brushed them aside with a soft brush and he quickly painted before they returned. Luckily the paint dried rapidly in the heat. Daft pair of softies!