How Far Apart Can Snap Traps Sit? A Wall-Coverage Rule for the House Mouse in Kitchens and Store Rooms

Households are usually told to place mouse traps a short distance apart, but no spacing is ever derived. This study models a house mouse making 60 m of wall-following travel per night along a 24 m run of kitchen and store-room wall, with each baited snap trap drawing investigation from 0.6 m either side, an investigation probability of 0.55 per zone entry, and a capture probability of 0.75 given investigation. Because the mouse re-crosses the same wall many times a night, capture probability saturates quickly: a single trap on the whole run still gives a 0.735 capture probability per night, and two traps at 12 m spacing give 0.93 per night and 0.995 within 48 hours, at a hardware cost of USD 4.80. The widest spacing that reaches at least 99 percent capture probability within 48 hours is therefore 12 m under the stated assumptions, and spacings of 1.5 to 4 m buy almost nothing except redundancy against a sprung or occupied trap. The originated rule is to space traps at up to 12 m on a known run, place them at wall junctions and behind appliances first, and spend the saved effort on nightly checking. This study is simulated, not measured. SIMULATED, NOT MEASURED.