I have tiiny tiny grain of sand like crawling insects coming fron behind the tiles in the shower I have tried every insecterside going sulphur bomb vinegar ant powder fly spray bleach disinfectant you name it I have tried it been to council and renakill no one can help they get all over th e walls I am worried that they will get all over the house
They sound like book lice. These are definitely small and almost colourless and like damp conditions. Is their any old wallpaper around your shower. It's just a suggestion. See:
http://www.bugsaway.com/booklice.htm