We had a ewe and a weeee baby bar lamb under our hoochie the other night......sheltering from the rain..... they moved pretty sharpish when they realised they had just woken up 3 hungry people in bivi bags.(BTW the biggest critter I ever had trying to get into my bivvy bag was a cat. Scared the life out of me seeing this paw push open the drawstring followed by its head!
I must admit I try and keep away from the chemical deterants.... covering up well seems to be the best preventative, and as martyn pointed out earlier... not all that flies bites!!! The bugs may be irratating buzzing around your face, but if they don't bite.... leave them to it.
Ed