We ended up trapping 5 cats but three were repeat customers who are so desperate for sardines they will get into a trap more than once. This means we are almost done with this colony after almost a year. Up next is one of the local trash disposal places.
The shelter supplies panacur and azithromycin. Feral kittens need a lot of that stuff. But not sardines. We recently got a donation of sardines from the local SPCA. That was all awesome. I made a promise to myself that I wouldn't eat any of them except for the ones that were left over after I baited the traps. My wife does not understand why I will totally eat any leftover sardines.