if your in the city of London, there are leash laws for dogs and CATS. Call animal control, they don't appreciate outdoor cats.
Animal control was quick to show up when we forgot to renew the tags for our indoor cat a few years back, to "remind us" but they won't do anything about stray and feral cats. Our cat has never been outside unless in a carrier. My wife had them before me and paid a small fortune for them. They're Siamese, so she's almost more protective of the cats than she is me. We used to have 2, but one passed a couple years ago. The other is 14 now, on meds, but very much alive and well.
We've had several feral cats over the years living under the neighbors place and in our yard. (the one year we had over 12 after the kittens born the year prior, all had kittens as did their mother.) The first year they showed up we called animal control and they told us "YOU catch'em. IF you manage to, you can bring them to the shelter on Pine Valley Road."
I was able to catch 3 of the kittens (out of 15) that we've seen in the yard over the past few years, until the mother moved them to a neighbor's place last year, (
guess she didn't like me trying to catch'em, or maybe it was the skunk that moved in under the neighbors place that forced her to move
) and when I caught them, I got them to the shelter where they were given vet care and then adopted out once they'd been "domesticated." which doesn't take long if they're caught within the first few weeks of being brought out from where ever momma has kept them hidden, but if you don't catch'em within the first couple weeks after first seeing them, forget it, they'll be too feral. They're hard to catch as it is, especially if their mother is wary of traps but without one, it's a game of chance.
IF you do manage to catch a feral adult cat and get it to them, they'll give it vet care, spay or neuter it, then release it back where YOU live because that's "it's known territory." and it'll be too feral to adopt out, so I was told by AC when I got the one kitten to them a couple years ago.