will be the only time. A cat won't fall for the cat trap trick twice.
Several years ago, we moved into a neighborhood that had a feral cat in residence. She had a litter of kittens, which disappeared. It turns out our neighbor had trapped them and was keeping or finding other homes for them.
On her next litter, we borrowed a trap from the neighbor. I set cat food in the trap for several days to get her used to eating in the trap. Then, one day, I armed the trap. She was smart, she stepped over the trigger plate and sat down to eat. One of her kittens, however, was not so smart and bounced right onto the trigger plate. Within a few days, the whole family was fixed and vaccinated.
Apparently, after she was fixed, she decided to move in with the neighbor. We kept the three kittens, who are now 9 years old. The girls are a bit skittish, but the boy is the sweetest little fellow imaginable.