A 2007 L. Robbins study observed that stoats might be attracted to mirrors. That had me bringing 50 3" diameter glass mirrors, found on Amazon, when I came last winter. They were added to 12 Doc 150 and 200s on a Ruahine trapline (Manaaki Ruahine) for a two month period.
The mirrors were glued onto a piece of cardboard which was then either wedged in place or held with small screws. Care was taken to align the mirrors so that the reflection wasn’t angled. Also the mirrors were periodically cleaned. The mirrors didn’t interfere with the lure placement. With these traps bait theft is prevented with the use of screen at the box top.
From January 14 to Mar 21 the 12 mirrored traps caught zero stoats but 14 rats. The 44 non mirrored traps caught 18 rats. 10 of the mirrored traps were consecutive even numbered traps. Those caught 10 of the 14. The intervening odd numbered traps caught none.
What to say about those results? It appears to have worked surprisingly well but more trials needed. I will be doing that when I return in December to my Northland trapping haunt. In the meantime a better use for a few makeup mirrors perhaps. My mirrors faced both directions. Would be interesting to see the results from a double with a one way facing mirror.