I also maintain Feral Cat Colonies,in some of the most dangerous neighborhoods in SF.
Some of These people want to know "what the F**k are you doing under my car??" at night kind of thing. which makes it harder to trap&feed.The BlackHawks are always finding new ways to do this.
THE SF FCSO
I trap manually,with coat hanger(cut)&string to trigger the cage.It can take weeks to 'Trap Train' a cat to go fully into the cage.Or get lucky the first time(after a lot of prep.) Some of our Cats have been returned to owners from being lost,some are trapped for being damaged orabandoned .Most are Feral...&TNRed.