People visiting Townsville's jewel in the crown -Magnetic Island- for the first time, especially those intending to tramp along the tracks , should be made aware that March Flies are out in force. One resident who has just made a return trip by car to West Point said that he was attacked by at least 40 of the critters when he alighted . Little Darwin understands the male flies like human sweat , causing a stinging sensation as they suck away , and are not deterred by being brushed away .Recent rain is thought to have brought them out in such numbers.