We prefer a double door trap, providing more options over single door traps, the option to use one door open with bait in the back, both doors open with bait throughout, or both doors open while using no bait at all. We use any of our 3x5, 5x5 or 6x6 double door swing panel traps along walls, any structure, with or without bait. Animals hug walls so bait isn't really needed but some black sunflower seeds speed the process. A big plus is that these traps never need adjusting like pan traps, but always have a light consistent trigger pressure when the panel swings as the chipmunks go under the one inch opening at the bottom. We made nose cones to go with each size so that the traps can be placed over den holes to catch chippies coming and going like we do for chucks and skunks. I like using traps that have multiple uses. These traps work great for chipmunks, red and gray squirrels, weasels, mink, barn rats, roof rats and for muskrats in runs under water. Additionally they may be used in any position, sideways, upside down or even set vertically on walls when used where squirrels are coming and going from holes in soffits and fascia. After the TRex quit catching, one trapper caught 8 barn rats climbing walls in a vertical set with a 5x5 swing panel trap. Tension on the panel can be varied by adding, subtracting or stretching the springs.