Shakespeare, Ben Jonson, Beaumont and Fletcher
Chapter 46
... “breeds fleas like a _loach_.”
Perhaps it is a misprint, or a provincial pronunciation, for “leach,” that is, blood-suckers. Had it been gnats, instead of fleas, there might have been some sense, though small probability, in Warburton’s suggestion of the Scottish “loch.” Possibly “loach,” or “lutch,” may be some lost word for dovecote, or poultry-lodge, notorious for breeding fleas. In Stevens’s or my reading, it should properly be “loaches,” or “leeches,” in the plural; except that I think I have heard anglers speak of trouts like _a_ salmon.