I’d like to share some of my thoughts concerning the use of double door cages with and without the use of bait. The primary reason for using double door cage traps, from my perspective, is to use them as you would a conibear type trap in trails, runways, den sites in positive sets, along structure, at craw-unders in fence lines etc. minus the use of bait. Used in this manner, bait is not unnecessary. Animals are going from A to B, just passing through. These blind sets have no lure or bait to distract animals just going about their daily routines. With no attractants, baitless sets intercept them. Set the trap and go. When they move, its over.
When using a double door trap with bait, which I don’t do all that often, I like to place the bait beyond the trap itself rather than in the trap. In this way the trap is again set like you would set a trap in a trail set. Animals are focussed on bait that is past the trap, with no reason to focus on the trap itself. They will have no reason to reach for bait or try to pull it forward as they are merely going through the trap to get to the bait on the other side of the trap.
Triggers on single door bait traps are located back farther into the trap than triggers in double door traps, which makes it more difficult for animals to back out when reaching for bait at the far end. For instance, a double door trap with a 36 inch catch box will have a trigger 18 inches into the trap, at center, while a 36 inch single door trap set with bait will have a trigger usually about 24 inches back. Baits can be wired in place to make it more difficult for bait stealers with either trap.
The idea is to use the shortest traps possible, to take up less space the truck and make them easier to place, while providing more confidence to the animal. If bait is to be used regularly its better to use a longer trap so that reaching and backing out is of less of a concern.
The mesh of the wire is of little concern when using baitless, trail sets for the most part, but mesh should be very tight, usually 1/2 x 1, when using bait in either single door or double door traps. If bait is used with larger mesh wire in double traps its a good idea to make sure the trap is butted up against something and the sides covered to prevent animals from reaching in from the back or sides. I tend to do it even with the tight mesh.
To a fault, I am an advocate of baitless trapping with double door cage traps. Yes, it does take some skill sometimes to figure out where to place traps and how to align them, but in the end eliminates variables associated with the use of bait or lure. I believe I mentioned using double door traps for gray squirrels with bait and found out that the squirrels at first took the bait from each end, never hitting the trigger in the center. Dropping one door cured that issue in a heartbeat. We missed a couple the first trip, then managed to nab 32 in row.