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 only cats that lick the tin are the ones in my kitchen afterwards I have removed all the tasty fishes from it. This happens more often than I like to admit.
I know that you are less offended by cat urine smell if you have Toxoplasmosis gondi, the most successful parasite on Earth, but I’m starting to be concerned that infection also makes you crave sardines.