In my hen house I made an additional tunnel parallel w/ the external wire.Aprox. 3' into the tunnel he encounters the live trap design;step on the plate,close door behind you,etc.I built my pen with a concrete stem all around so why would anyone want to burrow under when there is an obvious hole in the fence?It works!!! I have never lost another chicken but have collected a large number of varmints.

Good idea! I like it. Any pics?

Sorry no pics.Do you understand what I meant?The triggering mechanism is still; the old "
hav- a -hart" design,just elongated.I'm building one for my son now,will try to forward pics.As an addendum(since you are interested in good designs) Build your hen house proper at on end of your garden;build a dual concrete stem all; around the perimiter.Wire it in. The chickens can get loose in the3 A.M. _+ run the corridor;they cannot escape from the corridor.EVERY time anyone walks into the garden,the grasshoppers,etc. fly outward...into the corridor.Not a grasshopper out there than outrun a chicken.Hope this puts some ideas in your mind.