I was given xenox from the vet which I did use on one of my buns and his skin was really red, he also seemed to keep trying to lick it off. I have heard good and bad things about using rearguard, that it can be quite stressful for them trying to get it on, I clean their hutches every day but today I put them in an another run of ours on the grass and one of my buns had some softer poo and saw the flies on it, I've checked bun but doesnt look to be anything on her, they've always been fine in their hutch/run but they do have a waterproof cover over their hutch which probably keeps the flies out, she doesnt have any poo round her bum, is it only if there was poo round her bum the flies could attack?