Mruffruff beat me to the idea of tying open the trap. Feed them ONLY in the trap, at first place the food dish near the opening of the trap, then each day push it further in till they readily go in. Catnip does work great, especially for tom cats. Fresh is easier to use this time of year, as the dried stuff may blow outside the trap defeating the purpose. Put the catnip on the ground, and then put the trap over it so it's centered on the ground just past the trigger. Hopefully you have a one door unit, and not those horrid two door contraptions that you have to balance bars to set. The trigger won't fold down once the cat's trapped in them, and the cat is risking injury on the metal trip plate. Not to mention, sometimes the door will go down on the cat's back, and then forget about trapping that cat for a long time. Boiled and chopped up chicken livers work great too, if you can stand the stench from cooking them! Good luck, and hope you can get the other stubborn ones.