Old friend Valerio has two cats, yet they won't catch mice. I wondered to him if it might be a feature of urban, modern-day cats, because they're being looked after so well by humans.
The French farm that I used to go to had something like five cats at the beginning (on my first visit in April 1996), doubling (or trebling??) by 2011.
Whenever the farm mistress heard scuttling in the ceiling, she'd stop feeding the cats for a while, then take them up to the attic and release them there.
(France)