I discovered many years ago that the way not to get rid of rodents in
an organ is to bait them there! Bait draws rodents to the bait site,
and while they wait to die, they gnaw more and more. If you want to
bait rodents, the better way is to draw them away from the site they
are infesting, and bait them in a different place, far away from the
But the best of all ways to get rid of rats and mice, permanently,
is to buy a professional-sized electronic repeller. Some years ago,
Arndt Organ supply built and sold a real dandy repeller (they sell one
now, but no longer have that particular brand). It was about 8" high
by 4" wide, in a blue box, with a 3" speaker.
I know it works because we were having some really bad problems, having
received ( I think) a family of mice in a piano we were shipped, and
they set up house. Our bait was getting eaten quickly, and for weeks,
we had to keep the trays filled. We were finding dead mice all over
the place, and an occasional live one. I was also noticing gnawing
marks inside my own orchestrion in the living room.
The repeller stopped all that. They can't stand the sonic pain. I'd
place it close to the instrument you are protecting, and also put one
in every pipe chamber. They should have a power light to tell you that
they are actually working. Otherwise, how would you know?