This trap is similar to a couple of others designs of mine in that it features a thru-tunnel that won't spook mice who are leery of entering a dead-end space. The trap gets baited with a little peanut butter at the peak of the roof inside. As they go up the gentle ramp and work on the PB, the ramp tip, sealing the entrance. The two sides are coupled with little tabs at the end of the ramps, so that each ramp will trigger the other. When the ramps go up, there is a little print-in-place spring latch near each entrance (see 3rd photo) which locks the ramps in the up position.

The trap also comes apart in two pieces for easy release of the mouse and for cleaning. The two sides are held together with a slide-on clip.

One thing I've learned is from my other mousetrap designs is that once a mouse is trapped, it tries to gnaw its way out. Or maybe it's just bored. Either way, the trap can take a beating if you don't release the mouse quickly. In particular, they like to gnaw on edges. This trap features very few gnawable edges on the inside - mostly just a little tabs that interlock the two ramps, and even they are tucked against the wall and floor.

Printing
All parts are printed in PLA with 0.2mm layers and 3 perimeter lines. No supports are needed, but you may want a brim for the body and clip. Print 2 body pieces, 2 ramps, and 1 clip. After printing, the clip piece has a built-in break-away supports across the dovetail slots that need to be broken away.

Assembly
1. First take two short pieces of 1.75mm filament (about 50mm long) and put a slight kink in the middle (4th photo).
2. Hold the ramp in place with the axle hole lined up with the hole in the side of the body and insert the filament all the way through to the other side of the body (5th photo). It should be a slight friction fit. You want to be able to remove this hinge pin easily if needed.
3. Cut the ends of the filament hinge pin off flush with the sides of the body. (6th photo)
4. You'll need 4 thin rubber bands with an unstretched length of about 25mm. If your bands are too long, you can tie a knot in them and cut off the excess (7th photo). You may have to play with the rubber band length so that you get enough snap action to move the ramps past the spring latches.
5. Stretch the rubber band from the hook on the end of the ramp to the hook at the opposite end of the body. Do this on both sides of each trap half (8th photo).
6. Flip each ramp to the up position, hold the two trap halves together, and then slide the clip over the dovetails to lock the sides together.

Operation
1. Remove the clip to separate the halves and smear a tiny dab of peanut butter on the roof of the trap interior near the peak. Re-assemble the two halves.
2. With the trap sitting flat, press lightly on the inside of the latch while pressing down on the end of the ramp. It'll move enough to get the end of the ramp past the latch, but it won't lower entirely because it is still coupled to the ramp on the other side. While applying a little downward pressure on the 1st ramp, release 2nd latch while also pushing down the 2nd ramp. You can now push both ramps to fully open the tunnel to the armed position. Place the trap gently in the desired location.
3. You can tell you've caught a mouse if both doors have lifted to the UP position. To release the mouse, place the trap on level ground, lift up the clip and then gently pour the mouse out of one side or the other.