I can’t help it. Another idea using the last mouse funnel occurred to me.
What if you had a long tube with a series of bristles all pointing in the same direction just like the mouse funnel? Put some peanut butter on the outside, install in a door, and walk away happy and content that you’re saving mouse lives.
Once the mouse started down that tube it wouldn’t be able to turn around or back up easily. Given the option of unlimited freedom outdoors and chewing its way back through pokey bits, I can’t imagine it would choose plastic splinters.
Having fought an almost constant war with mice, I think you’re underestimating the determination of a hungry mouse. If there’s any opening at all, they’ll squeeze through it. They’ll also chew holes through anything flimsy like the plastic slats of your funnel.
I probably am underestimating mice. It has been a really long time since I’ve had to deal with them.
So, you really think a mouse would rather crawl and chew threw, say, a six inch long tube filled with stacks of bristly funnels (flimsy though they may be) rather than arrive at the far end, eat some peanut butter, and then just go do something else?