Catrin - have you tried lemon eucalyptus? It's marketed under a couple of names, I've purchased Repel from REI. For me, it actually works on mosquitos better than anything I've tried. I've been out near dusk around shallow water and not been bitten, which is amazing. I can see them swarming around, but they veer off when they get too near. It's quite incredible to watch. We've usually very few ticks out here, so I can't speak to it's effectiveness against them. It's not effective at all against biting flies and the little gnats that don't bite but are annoying in their determination to get into your eyes and nose. They seem to enjoy the scent… but, it doesn't melt plastic or destroy your clothing and it has a relatively pleasant, if fairly strong odor.