Just saw esshup's hint to bait traps with styrofoam peanuts. That is brilliant! If it works, it isn't hard to keep a ready supply. I wonder if color peanut matters? Obviously there is white peanuts but sometimes I get pink green or blue as well. The peanuts are visual only to improve trap rates, but you would still need a 'food smell' of some type to get them closer?

The other thing I have handy is dog food (no fish food) but that dissolves and tends to go away. I wonder if other small bits of styrofoam would work?

I've read that for crayfish one of the best baits is a can of tuna fish with the top kept on but small holes drilled in the top to allow the fish oils to slowly ooze out. I thought this was another great idea. I'm going to be sampling my pond for crayfish soon to see if I have any survival and who knows, maybe I can catch some minnows as well.

I've read leeches can be caught with a sealed metal coffee can with holes drilled in a way that the leeches can just squeeze through the hole but the deformed metal on the inside of the can (the burr of the metal) is left in place so they can't come back through. On my list of things to try

Bill Cody thought you would get better yield if the metal was bare, or painted a drab color on the trap. Those are harder to locate so I wondered out load with him if one could put a metal wire on the trap and throw it in a campfire, or maybe use a torch to burn off the plastic coating on the ones that are for sale by me. IF successful they would likely start rusting soon so would want to be primed and painted once they cool down. Not sure how effective that would be but could be tried.

IF Farm and Fleet have truly metal traps with no coating and black paint then you should be good. My trap has hot dip PVC or something coating it.