Hello Mr Yorkie, I did fervently hope, I would not have to explain this , in simple terms, so I must apologise, if I am posting this to you, under the wrong heading.
As I am probably, one of the most senior posters, on this web site, so far be it for me, to be teaching anyone, a little of Britain's history! As aboy in the 1930's, Britain's houses, were small, cramped, and very close together - so were a breeding ground for Fleas. Bathrooms, were a luxury, not possessed by the working class. nor were there such clothes as ''Pyjamas'' - so the normal working man, such as all my Father, Uncles, and Grandfather, too, came home, bathed out in the Scullery or brewhouse, (Kitchen), then, if retiring for the night, donned a ''nightshirt'' and went to bed. If, as often happened there was a flea in the bed, biting all in sight, & you needed to remove it, and you foolishly put on a gas light, or lighted a candle, the flea would qucikly make an exit, so fast - the trick to solving this dilemma, was to feel for it, biting, then trap it, in your nightshirt., and squeeze the very life out of it, with fingers, and thumb.- Along came Keatings powder - which solved the problem, as more inhabitants, used the powder, and so killed off thousands of these pesky fleas.. I am amazed, Mr Yorkie, you had to ask. But not all can be as informed as me, I suppose.. Thanks for asking - dontheturner..