Much to my chagrin, we have four cats, although I won't let the most recent cat inside. The other three used to get snarky at times, until my wife started drugging them....with cat pheromones.
The stuff we use is called "Feliway." It works with a diffuser that plugs into the wall, and it costs about $12 for a bottle that lasts a month. The cats often just hang out around the diffuser and look happy, and they seem to be in a good mood most of the time.
Works for us. Hey, Lox, do you think it might work on Mudcatters? I was thinking of singing lullabies to aggressive Mudcatters, but maybe pheromones would work better....or maybe I should save twelve bucks a month and sing to the cats?

-Joe-