I have a couple of that style scissor traps and have caught more than I have fingers, but I am not as successful I would like. I guess I don't have the placement technique correct. To date though, everyone I caught was dead... no maims.....
What I like about the out o sight traps is that you can set them at any depth, and in almost any soil conditions, with fine or sandy soil being the hardest, because as the mole digs under the trigger pan, the sand falls away.
What works best for me is to never trap the areas that look like wrinkled up carpet or never trap the mole hills. The wrinkled up carpet is where the mole is just rummaging around right under the sod and you can almost never guarantee he'll be back to where your trap is. And mole hills are vertical tunnels where moles just push up excess soil to get it out of their tunnels. It'll trip the trap well before the mole's body gets anywhere near the trap.
So I look for longer sections of tunnel, and use my heel to press a good indentation into the tunnel about every 10' or so. When I check the next day, if the indentations I made are gone, I know that's an active tunnel, and that's where I set my trap. I use marking flags to keep track of my indentations...
I make two cuts perpendicular to the tunnel at the width of the trap, and pull out the sod plug. Then I dig down till I find the tunnel, just removing soil to the bottom of the tunnel, so I end up with a rectangular box going down with a half pipe of the tunnel for the bottom. Then I replace the sod plug pressed down firmly against the half pipe, making sure to barely cover the open tunnels on each end of the box. Then I set the trap and safety, and use the setting bars to lower the trap down against the sod plug, with the jaws straddling each open tunnel area. I usually push it down till the trigger trips, then reset it. Being careful to keep a grip on those setting bars!
So now we have a sod plug set firmly against the bottom of the tunnel, and the trap trigger set firmly against the sod plug, and the jaws straddling each tunnel opening on either side of our dirt box.
If the mole comes from either direction, he senses the tunnel has collapsed, and sees a bit of light coming in. So he pokes under the sod plug to lift it up and re-open the tunnel while closing off the light. As he scoots forward between the scissors jaws, when is front paws and head get near the trigger, it pushes up the sod plug, trips the trigger, and the jaws close around the center of his body. It's enough force to break human skin and bones, so it's enough to kill the mole quickly in most instances. Which is what I'm after.
Anyhow, moles are pretty amazing critters. I've read they have twice the number of red blood cells per ML as humans, so they can survive in lower oxygen conditions. If a mole was 6' tall, it could walk between parked cars and shove them apart. And they don't hibernate. They just go deeper, down to the level where the food isn't frozen.
