A mouse keeps outsmarting me!

[cuda hunter]

I've always seen the round ones with holes also.

but a flat piece with a T on it makes sense.  That would work just fine.  No holes needed or extra engineering. 
Although once it's triggered you only get the one until you reset it right? 

[Chryco Psycho]

depends , mine would reset , counterbalanced to tip with the weight of a mouse & tip back without

[JS29]

I wonder if it;s his chipmunk friend that is the culprit! I have seam those striped vermin do enough damage to a car, that the owner had to use there comprehensive insurance to pay for repairing it.