Sand flies are a reality in New Zealand. For the first few days we would encounter them occasionally; but, as we moved into the western coast/temperate rainforest they have become obnoxious. I can best describe them as the size of a gnat with the bite of a fire ant and it has wings. At first you may or may not feel the bite and it is less than a mosquito bite. The true issue comes for the next few days when a blister develops and the itch is nearly unbearable. It seems the more you scratch the larger the blister and the greater the itching. DEET slows them down but does not stop them. Fortunately, we found that Aloe Sunburn gel takes a bit of the itch away. Whew! Lucky for me (Lynn) the flies like Kent better!