Rodent proofing CG Hook

Keep in mind, dryer sheets and/or moth balls (did you spread its wing to sniff them?!?!.....dad joke....) are supposed to be a deterrent.
When they run out, or rodents can't smell, a mouse/Chipmunk/mole can fit through a dime sized hole, rats can get through about a quarter sized hole.
Keeping them away is good.
Keeping a food source away is also good.
Keeping them out if 1 & 2 fail........sorta problematic. There are quite a few small holes underneath most aircraft that rodents can get through.

Taken from someone that has dealt with this and has a major consultant in the pest control industry as family. I have asked these questions before on other applications.

Our local rodents are not deterred by moth balls.

Rodent leavings in the cockpit can be a small fraction of what's under the seat pan.

At 02:42 28 February 2019, George Haeh wrote:
The club Grob had copious evidence of rodent infestation

Might be an idea to check the aircraft out for damage, if not already done
so. Had a Twin Astir one day that had all the foam supports for the rudder
control rods gnawed away, leaving only the nylon guides dangling from the
rod. Nasty repair, too.

On Friday, March 1, 2019 at 3:45:05 AM UTC-5, Eric Munk wrote:
At 02:42 28 February 2019, George Haeh wrote:
The club Grob had copious evidence of rodent infestation

Might be an idea to check the aircraft out for damage, if not already done
so. Had a Twin Astir one day that had all the foam supports for the rudder
control rods gnawed away, leaving only the nylon guides dangling from the
rod. Nasty repair, too.

I've always used moth balls, never had a problem. Usually put them in place middle/end of November and remove in end of march/early april. When removed, they still have a strong smell. I usually place a packet of them on the seat, near the rudder pedals, where the wing spars go in the fuselage, in the front of the trailer/wing root area and under the rudder; this seems to cover the obvious entry points and I've never had an issues with rodents to date. The odor goes away within a few days of removing them and it's never been so strong that it's bothersome for the first flight of the year, assuming you can keep a vent open. I've never tried the scented dryer sheets, but may do so next year?

On Wednesday, February 27, 2019 at 9:42:30 PM UTC-5, George Haeh wrote:
The club Grob had copious evidence of rodent infestation and we found that the CG hook opening offers a wide passage. We cut out a piece of aluminum, glued a stack of disk magnets to hold it to the tow hook inside the cage and put on a drawer pull. Also taped inside to protect the finish. Will add some flagging tape so we can find if somebody forgets to remove before towing to runway.

https://photos.app.goo.gl/UugfLA5Dopg1Ebn88

https://photos.app.goo.gl/eDKQaFX4E9hHVRuT6

Make cover out of a plastic ladle with internal loop;
pull the release, engage the loop, lock the cover over the release.
JMF