OF MICE AND AEROPLANES: Things Every Pilot and Aircraft Owner Should Know.

[Garth Elliot]

I have gleaned the following from the internet – and other sources:
Mice can jump an average of 12 inches vertically and four (4) FEET horizontally!
Exceptional mice can jump 18 inches vertically.
They are known to gnaw on wood spars and rib stitching. I have seen some really messy results...potentially life threating when the aircraft is aloft.
It takes an exceptionally SMOOTH surface to prevent them climbing vertically.
Their urine is not nice -can lead to corrosion, as well as infection.
Their scat (droppings) can be dangerous. Collected in a fuselage, scat can be a gathering place for moisture -hence corrosion. It also is dangerous as a source of infection.
They carry many dangerous diseases…including the formidable Hantavirus.
They can pass through holes as small as 1/4 inches. They can flatten their bodies to enter incredibly small spaces. Even small bats (We should call them flying mice?) can get into incredibly small holes.
If you want to keep mice out of your aircraft...I think the following might work. It might prove satisfactory to use a very smooth galvanized metal ring (collar) around the main gear and the third wheel should have a ring around it. If you have a taildragger the ring on the tail wheel might be quite large in diameter in order to clear the lower rear fuselage and any tail brace wires and the rudder. The height of the metal rings should be (safely) 19 inches although 13 to 14 inches might be enough for the average mouse...but not enough for competitors on Mouse Olympic teams.
Properly designed rings should easily encircle the wheels and then clip together to form a complete circle. Where they clip together the joint should be very smooth and run vertically.
Keep the aircraft at least four (4) feet away from walls, boxes, other aircraft etc. -to prevent mice from jumping from one place to another.
Consider putting baited and simple mouse traps inside the rings...as a secondary precaution.
It is possibly very unlikely that chemicals or electronic mice "discouragers" will actually work. Mice can get used to electronic outputs -and often just walk on by chemical "discouragers".
Chemically poisoned mice can die ANYWHERE -even inside your aeroplane, your toolbox, a carton, or on the hangar floor. Handle with care. Wash your hands afterwards.
I know of some insulated hangars where the mice live in the wall insulation -also the ceiling insulation. In the ceiling they mimic bombers and sprayers…

Climbing walls, they can be very adept -acrobatic even- although I have not yet observed any vertical rolls. Lomcovaks and rolls on descent but no climbing vertical rolls. Not yet! (Perhaps with time...?)
If the aircraft is parked outside and there is a heavy snowfall, all bets are off! The rings will be covered/filled with snow!
Rings used outside should perhaps be staked down when installed because in heavy winds they might bounce around and cause damage. Needless to say the aircraft should be well staked lest it bounce against the rings. (The main target of what I write here is the hangared aircraft.)

Try to smooth off the upper edges of the rings –possibly by using rubber channeling in order to prevent injury to visitors…with resulting litigation.
Perhaps others will be willing to share information/suggestions on this topic…

A simpler and better solution would be pleasing indeed.

The photos here show devices made up by Dan Hieronimous for his
Marquart MA-5 Charger homebuilt biplane. They encircle the gear and clip together to form a mouse barrier.

Garth Elliot
Ontario, Canada

[Mike Switzer]

A simpler and better solution would be pleasing indeed.

I find the scent of Tomcat pee to be a wonderful deterrent - of course if he sprays everything in sight it keeps the human females away also....

I had to have my tom fixed last year as he was getting too old to win every fight, but between him & his boy there are no mice in my barn unless they bring them in for dinner....

[Frank Giger]

Assuming that there isn't a launch pad of a box or shelf for a mouse to leap onto an aircraft, the humble glue trap next to wheels will do; mice jump vertically to get up onto surfaces.

One of the big things to do about mice is to try and remove all food and water sources in a hangar. That includes open (but empty) water bottles and Coke cans....and then get the guy next to you on either side to do the same thing. Glue traps on the sides of the hangar door and at other entry points along walls work well, too. Mice work the walls, and use a trail system like most other mammals.

The next is to remove as much nesting habitat as possible. A cardboard box full of rags and stuff next to a wall is like the Hilton for rodents. If you don't really need it in the hangar, get it out!

I'm not a big fan of rat poison for the mentioned reason that they'll craw up into holes to die. Performing the dead rodent search is never fun.

[Racegunz]

Perhaps hiring me to fly the plane more often will keep the mice out?

[steveinindy]

They are known to gnaw on wood spars and rib stitching. I have seen some really messy results...potentially life threating when the aircraft is aloft.

LOL Add this remote possibility as yet another reason why I won't be building a wooden or canvas aircraft. LOL

If you want to keep mice out of your aircraft...I think the following might work. It might prove satisfactory to use a very smooth galvanized metal ring (collar) around the main gear and the third wheel should have a ring around it. If you have a taildragger the ring on the tail wheel might be quite large in diameter in order to clear the lower rear fuselage and any tail brace wires and the rudder. The height of the metal rings should be (safely) 19 inches although 13 to 14 inches might be enough for the average mouse...but not enough for competitors on Mouse Olympic teams.

That's a great idea. Thank you for sharing it with us.

They carry many dangerous diseases…including the formidable Hantavirus.

....and this is an issue even outside of the southwestern United States where most of the focus on hanta (or the "sin nombre virus" to use the older name for the hantavirus pulmonary syndrome) has been.

A simpler and better solution would be pleasing indeed.

It reminds me of the old military aircraft maintenance joke:
Squawk: "Mouse sighted on aircraft. Droppings noted"
Fix: "Droppings removed, cat installed."

[Bill Greenwood]

I have read that putting several sheets of dryer fabric in your baggage area will repel mice. They don't like the smell. By dryer fabric I mean those sheets that you put in the dryer to soften your clothes. I have used it in my plane, seems to work. I don't know if it has and side affects.
We had some problems a few years back when planes were parked at the north end of the ramp and the nearby field mice were disturbed by some work in the field.They are also attracted to any food in the plane. I once flew a man to a nearby town for lunch. He insisted on bringing the leftovers back with him, "so as not to waste any food". Unbenownst to me, he put the package on the rear baggage shelf and forgot about it. That defintily drew mice. Once they mowed the grass down and paved over much of the field, and also we park farther away now, I haven't seen signs of mice.
As for hanta virus, from what little I know, it seems pretty rare, not likely to be in any airplane in regular use. It is more likely in dry areas in some out building and in New Mexico, maybe sw Colo, in a dusty area.

[steveinindy]

It is more likely in dry areas in some out building and in New Mexico, maybe sw Colo, in a dusty area.

The chances of it coming from exposure in an aircraft is pretty remote, but the geographic limitations are less important than originally thought. That said, having seen a case of HPS firsthand, it's not something I'm particularly willing to chance if I can avoid it.

[Bill Greenwood]

The hantavirus has occured in other countries and in about 8 states in the U S, but the most U S cases were in N M and Colo, then Az near the four corners area.
It might be transmitted by rodent bites, but more likely by breathing the dust from dry rodent droppings.

[steveinindy]

The hantavirus has occured in other countries

Yeah, the name is derived from the Hantaan River where the family of viruses was first described from after it caused high morbidity and mortality due to renal failure amongst US and UN troops during the Korean War. This is now called HFRS (hemorrhagic fever with renal syndrome).

about 8 states in the U S

That's only if you're strictly counting the "Sin Nombre" variant. There are several other strains of Hanta virus and the distribution is fairly wide:

"Regions especially affected by HFRS include China, the Korean Peninsula, Russia (Hantaan, Puumala and Seoul viruses), and northern and western Europe (Puumala and Dobrava virus). Regions with the highest incidences of HCPS include PatagonianArgentina, Chile, Brazil, the United States, Canada, and Panama, where a milder form of disease that spares the heart has been recognized. The two agents of HCPS in South America are Andes virus (also called Oran, Castelo de Sonhos, Lechiguanas, Juquitiba, Araraquara, and Bermejo viruses, among many other synonyms), which is the only hantavirus that has shown (albeit uncommonly) an interpersonal form of transmission, and Laguna Negra virus, an extremely close relative of the previously-known Rio Mamore virus. In the U.S., minor cases of HCPS include New York virus, Bayou virus, and possibly Black Creek Canal virus." (SOURCE: WIKIPEDIA)

[Garth Elliot]

I recently saw one very frustrated mechanic/friend trying to repair the belly damage in an all-metal Cherokee. Serious corrosion was occasioned by the build-up of mice droppings and urine. All-metal construction sure is not a protection. No matter the type of construction, PREVENTION is the "hands down" best fix!
Mice have been known to chew on wires too!
Sealing all cracks and spaces allowing mouse entry into a hangar is all too often overlooked. Funny how we spend a fortune to build or rent a hangar and then do not cover some very basic things. Rain, sun, ice, snow, frost and heavy winds are very undesirable things....but mice? Mice? You gotta be kidding! Who ever talks much about mice?