War has been declared. We have been noticing a growing catty smell in the hallway. Eventually, we thought to turn over the mat in the hall, and the pale fabric on its underside clearly showed the marks of many and repeated puddles. Today, we got a new mat, and also got bottles of things with gratifyingly pugnacious names, along the lines of "Get off and stay off!" or "Oi! Cat! Get off my land!" The hall has been thoroughly anointed with these things. One cat has gone outside, looking very sulky; the other is cowering under the spare bed, glowering. I'll win this battle.