Do you eat lots of garlic? Not sure of exactly what other menu items but I do recall reading somewhere that diet has a lot to do with your attraction/repelling of them.
Yeah I eat a fair amount of garlic I spose but I've never really been bitten much even as a kid when I hated garlic and 'foreign food', I always put it down to my blood group but it could well be something else that I eat? Definately not marmite though, can't abide the stuff. Perhaps they do bite and I just dont react to the bites, I've never really taken much notice to be honest cause they don't bother me much they're just annoying. Ex-wife would come out with lumps the size of half golf balls though, they used to eat her alive bless her.
Si