well my birds all have either a perch or box from this ill remove a single dropping from each , then i get a knife and mix into a paste then this is what the vet tests and yes id treat the entire loft the same , my stock cocks only mix with stock hens my race cocks only mix with race hens stock hens and race hens are kept together at this time of year so this loft will be the one where younger birds and older birds are and more likely to have a wider range of my colonys problems as old birds are more robust and ybs arent so this is how i do it , if i had a problem back end of season and been to vets i would probably only treat with tkk and for worms nothing else , but i find its more benificial to my pocket and birds health treating for conditions that need treating