How To Shoot Them Down

A jetliner traveling from Los Angeles to DallasFort Worth reaches cruising altitude. The captain turns off the seat belt sign and the flight crew prepares to serve beverages to the passengers. One of the flight attendants sees movement out of the corner of her eye. Refocusing her attention on that area, she sees a mouse dart across the galley.

Fantasy? Unfortunately not. Mice can be common hitchhikers on aircraft, and rats are occasionally found aboard airplanes as well. Rats and mice generally keep hidden while an airplane is in operation, so sightings are less common than they might otherwise be.

Rodent infestations on aircraft are usually found when the droppings are seen during cleaning or maintenance activities on the infested aircraft. When infestations do occur, usually only one or two rats are involved, but a larger number of mice may be present on a single aircraft.

Rodents are of grave concern on jetliners due to their propensity to gnaw on items, particularly wiring and hose lines. Jet air craft are complex machines that contain thousands of feet of wiring and hose lines, so any rodent sighting must be taken seriously and immediate action must be taken to eliminate their presence.

BOARDING PROCEDURES. Mice can easily gain access to the cargo compartment of an airplane as the cargo is being loaded. This is probably the most common way that mice are introduced onto aircraft. Rats, on the other hand, likely climb into aircraft using the landing gear while the jet is on the ground.

It is also possible for mice and rats to access aircraft from the jetway or from service vehicles attending to the aircraft — food service trucks in particular.

It is also rumored that during Chinese Years of the Rat (which occur every 12 years: 1972, 1984, 1996, 2008, etc.), jetliners flying out of Hong Kong during January will have a rat clandestinely released upon them. The release of the rat is supposed to bring good luck, but unlike seagoing ves sels, a rat's presence on an airborne vehicle can create significant danger.

Control Strategies. Rodents can be more difficult to eliminate from airplanes than from buildings for a couple of reasons. First, airplanes cannot be held in one place for more than a few hours, and usually only overnight. It costs an airline or delivery service a great deal of money for each day one of its planes is grounded for any reason. In some cases these costs can be in the hundreds of thousands of dollars.

The fact that an airplane may be housed in different cities each night of the week makes the followup services that are necessary for rodent elimination nearly impossible except for national pest control companies with offices in many cities.

Rodent control devices are not permitted to be left in place while an airplane is in flight. Traps and bait stations can be placed only when the plane is on the ground and then must be removed prior to the plane resuming flight operations. Such short periods of device deployment can be effective for mouse control. Rats, on the other hand, can be extremely difficult to capture or kill without being able to leave devices in place long enough for target animal to become accustomed to them.

Baits on Aircraft. The use of solid and liquid rodenticide baits is not generally recommended for a number of reasons:

• It is important to retrieve the rodent carcass. Otherwise it could end up in some sensitive area of the aircraft, such as the electronics and avionics compartment.

• A dead rodent on an airplane could create an odor that could prove especially noxious in an enclosed space. It would be difficult to find the carcass that is creating the odor because airplanes have numerous spaces that are difficult to access.

• Rodenticides can take up to a week to kill rodents, and the quick removal of the rodent(s) from the aircraft is of paramount importance.

• Despite the best efforts during regular cleaning, sufficient food to support a small rodent population continues to be present. Also, condensation created inside a jet aircraft body during one flight can create up to 10 gallons of water — more than enough for one or a few rodents.

Traps. Trapping is by far the most efficient solution to rodent infestations on aircraft. As mentioned earlier, however, this strategy is made difficult because aircraft are often in different cities on consecutive nights, resulting in shortened exposure periods for the rodents to interact with the traps.

• Mice. In order to eliminate a rodent infestation from any structure or vehicle, each rodent in the population must encounter a trap and then interact with and commit to the trap. Accomplishing this with mice is much easier than with rats, because rats are more cautious creatures. Still, any mouse may completely ignore one particular type of trap. For this reason, every type of trap available should be used to provide each mouse on the aircraft with an opportunity to interact with at least one trap — and, hopefully, to commit to it.

Snap traps should be baited with a variety of baits, including bits of cotton, which mice find attractive for nesting materials. Use both Tin Cats and one of the different brands of wind-up mouse traps — KetchAll, MouseMaster, Kwik Catch— to provide a greater variety of choices for mice. Cardboardbacked glue traps should be used inside 2-inch or 3-inch lengths of PVC pipe and placed along likely mouse runways.

In addition to using a variety of traps, it is extremely important to use a large number of traps. The single greatest mistake made when attempting to quickly remove a few mice is placing too few traps.

When placing traps for mice, place them only a few feet apart throughout the aircraft and alternate the different types of traps. Be sure to place traps in the galley, lavatories, closets, and cargo holds. An airline maintenance person must be present for any traps to be placed in the cockpit and to remove any ceiling panels to provide access for trap placement. The same service personnel who set the traps should also be the ones who retrieve the traps the following morning in order to prevent any trap from being overlooked during retrieval. If traps are placed in the ceiling or inside enclosed spaces, place a large red adhesive dot at each of those locations as a reminder that a trap is present.

• Rats. Rats are considerably more difficult to catch than mice, even in a building where 24-hour access is available. Possibly the most difficult situation encountered in structural pest management is the removal of a rat from an aircraft. Such efforts require cooperation from airline personnel in multiple cities as well as coordinated efforts with fellow members of the pest control company in other cities.

Due to a rat's suspicious nature, traps may need to be in place for several days before the rat will even interact with them. This is not possible for an aircraft that is in service. However, by using a diagram, the same type of trap can be placed in nearly the same location on successive nights, even if the aircraft is in different cities.

Snap traps, glue traps, and live traps are the only types of traps available to capture rats. Of these, snap traps are typically the most effective. Because fresh food may not be available to a rat on an aircraft, however, the rat may interact with a snap trap that has a fresh bait. For this reason, snap traps should be set from the first night in the event the rat may interact and commit to the trap. Use the expanded-trigger snap trap model and use a variety of different types of bait attractants. Snap traps need only to be placed in areas where rat activity has been noticed — particularly in, above, and below the galleys. An airline maintenance person will need to be available to access voids where the rat might venture, such as in the ceiling. In the unfortunate event that the rat sets off the trap and is not captured, it probably will shun all snap traps and become wary of other types of traps as well.

Commercially prepared glue traps should not be used in these situations because rats often escape glue traps and avoid them thereafter. Prepare your own glue traps using thick layers of bulk glue. These traps should then be placed along active rat runways, such as in the ceiling.

Live trapping is probably the least effective trapping technique for rats, but it may be useful in some situations. Such traps may be baited with a food bait or a small bowl of fresh water.

It may take numerous services to finally catch the rat(s) on an aircraft, but success is generally achieved within a week or so. Periodically, however, a particularly cautious rat may be encountered and extreme efforts may be necessary to catch it. In such cases, the airline may have to ground the aircraft for several days so that increased trapping efforts may be deployed. Rodenticide baits may also be tried if the rat refuses to interact with traps. If such a case is encountered, it is best to seek advice from one or more rodent control product manufacturers or consultants specializing in rodent control.

Fumigation of aircraft is not longer performed in the United States, but may still be available as an option in some countries. Needless to say, aircraft fumigation requires a very experienced fumigator, and fumigation should only be attempted as a last resort.

CONCLUSION. Rodent control on aircraft takes effort and experience. Coordination with persons performing service on the same aircraft in different cities and with the airlines is critical to success. Take care to plan out the trapping strategy and follow up to ensure complete elimination.