i’ve rented a wire trap cage to trap two feral cats on my property, with priority to the femal that is already in heat, but no luck… i’ve put sardines inside, another time fresh tuna and other foods but she’s not bit’n!
Where is the trap? Often, feral cats don’t want to cross open areas, even for something yummy. Try putting the trap in some bushes or cover it over with something. She also might not have noticed it was nearby (this is less likely, but not impossible). Cats have a good sense of smell, but it’s not crazy. I’ve seen my own cats get within half an inch of a newly split orange peel before they realize what it is. Put the trap near where you usually see her.
And, as a last resort, she might not like fish. Strange, I know, but I have seen it. Don’t know if a feral would really turn down any food, but whatever. Try picking up some cheap little cans of wet cat food like Friskies in different flavors. Since it dries out after each day, you can rebait the trap with a different flavor each time.
Good luck
Pullet has some good advice. I used to trap cats for a living, and some of them are more difficult than others to trap. As stated above, make sure the trap isn’t just out in the open. If you are able to observe the “trails” the cat uses to move around, place it on or near one of those. Covering it is also a good idea - something not strongly human scented or dryer sheet scented is best. This also helps keep the cat from stressing out as badly after it is trapped.
Bait? I usually used canned cat or dog food, but for difficult cases I would get canned mackerel (use gloves - that stuff stinks beyond imagining) - or, for the really difficult ones, fresh warm fried chicken, the greasier the better. (Churches chicken never failed for me) Of course, you have to pull it off the bones.
Good luck.
Curse you, Snakescatlady.
And curse this tiny town with its one, non-Churche’s chicken restaurant. 
I don’t know your location, but if you’re inland, a feral cat may not know that fish is good to eat.
Heh.
This may be obvious, but make sure there’s no neighbor feeding them: it’ll work a lot better if the cat’s hungry.
Daniel
It’s unusual for a kitty not to like fish, though I’m sure there are some out there. It might be down to the kind of fish (or seafood). Just now I was making a mackerel salad, and my cat didn’t react at all, even while I was flaking the mackerel. Then I opened a can of lobster terrine, and within a half-second she went absolutely bananas. Crab meat has a similar effect on most cats I’ve known - they can smell it almost instantaneously from yards away, so maybe try that.
Great Suggestions! Thanks!
I do know her trail around my property, so rather than leaving it out in the open on my back deck, I’ll rest it near the trees on the side and cover it up (another great suggestion!).
I sure hope this works!