Integrated Pest Management(IPM) Principles for Rodent Control
IPM Principles: It is the best policy to look for rodent entryways and food sources at the same time rodent traps are set out. The locations of caught rodents will help to identify routes of entry. Mice often enter apartment units via the radiator pipe opening in the walls. Use a large number of traps to quickly reduce populations inside of buildings. Do not place traps outside of buildings unless they are secured in a tamper-proof station. The snap trap is considered to be one of the more humane methods of removing rodent populations.
Adjustable Snap Traps: Most professionals prefer this style of trap. Both a mouse size and a larger rat size trap are available in most retail outlets. The trigger clasp can be adjusted vertically to hair-trigger the trap.
- Extended Trigger: This option provides a larger surface area for contact with mice and is sometimes used by professional pest control contractors. Attach a small platform such as a piece of cardboard under the bait clasp so that it expands the trigger contact area.
- Quick Setting: A plastic snap-in-place trigger is used to make trap setting easier for the novice. The most common form of this style of trap has a yellow plastic bait clasp with a V-notch for bait placement.
Bait: A variety of baits including peanut butter, crackers, salty meats, bacon, fruit or grain are effective. Peanut butter bait usually works best and does not dry out as quickly as cheese or other moist baits. You can use the same food that rodents are known to be feeding on in the area although different nutritionally desirable baits may also be effective. Do not over-load the trigger with bait. For mice, place small amounts of bait inside the curved lip of the bait clasp. For rats, tie solid baits to the clasp with wire or thread. Replace regularly to keep baits as fresh as possible. If cockroaches or ants are removing food baits, use cockroach or ant gel baits in addition to the rodent bait.
Setting Adjustable Snap Traps: Hold the trap firmly with the left hand, with the baited end facing away from you. Pull back the trigger bar with the right hand. Then hold down the trigger bar with the left hand, and place the trigger rod against the trigger clasp with the right hand. Slowly release pressure with the left hand. Now shift the trap to the right hand, and firmly set the trap in place. To improve trap sensitivity, the trigger clasp can be adjusted vertically. This trigger adjustment allows the rodent to spring the trap with minimal contact. If the trap accidentally goes off while being set, you can push the trigger clasp more horizontal to increase resistance.
- Placement: Set snap traps in locations that interrupt normal rodent pathways. Place traps with the baited end perpendicular to walls so rodents will be caught approaching from either direction. Place traps in front of rodent harborage openings, inside pipes, and between walls and equipment to improve chances of trap contact.
- General Information: Snap traps are normally quick acting, killing the rodent immediately by breaking its back. Large adult rats may not die in the trap, but may recover or die later from sustained injuries. Traps can be re-used if not contaminated with large amounts of blood or other fluids. Set out many traps in an area to quickly reduce a heavy infestation. Wear gloves and wrap dead rodents in a plastic bag and dispose of bag in an outside trash container.
- Caution: Place traps so the cleaning crew, staff, children or pets do not accidentally set them off. Place traps so that the caught animal will not fall into food or other sensitive locations.
- Special Tips: Traps can be placed first with the bait present, but the trigger not set to attract wary rodents. After pre-baiting, the trap can then be set to improve capture success. If a trap does not operate on a rat correctly the first time, the rat may become trap shy. If rats are suspected of being trap shy then cover the base of the trap under a surface such as loose sand or paper.
Multiple Capture Traps: Multiple-capture live traps such as the Tin Cat® and the
Ketch-All® traps are effective for mice (and young rats) and save time in disposing of the captured rodents. These traps are more expensive but are capable of capturing several rodents. These automatic traps do not require a bait attractant, the rodent enters the trap to investigate or to approach other rodents already captured. Newly trapped rodents can be drowned within the trap.
Glue Boards: Snap traps can be supplemented by using sticky traps to capture mice in narrow spaces such as behind radiators or under refrigerators. The hot melt adhesive stays sticky over time and mice that are captured allow removal and disposal of carcasses and any external parasites such as mites. Some people object to this method of capturing mice and their concerns should be respected.
Anticoagulants: Poison baits are not recommended for use against rodents. Death due to internal hemorrhaging is a slow process and the rodents will decay and smell offensively behind walls. Numerous carrion flies will breed within the dead rodents as well as carpet beetles and a secondary pest infestation will result. Rodent bait is a potential food source for beetles, moths and other food pantry pests that can later move to attack food stored for human use.
Ultrasonics: There are a variety of ultrasonic and electromagnetic devices on the market. Most are sold through mail order houses and all are suspect as to value. You may be guaranteed satisfaction or your money back but you may wait a long time to see a refund. There is scientific evidence that mice habituate to high frequency fluctuating noise the same way people habituate to noise at a sports or music event.
Copper stuffing material. The 100% copper mesh comes in a roll. This material can stuff and seal off many types of smaller openings. Copper is much better than steel wool and is available to professional pest control vendors.
Foam sealant is not rodent proof. You can often see recently chewed openings in the foam. If foam is to be used then it should cover an under structure of tightly packed copper mesh.
Final note: It is always best to seal out mice entryways and eliminate the rodent food source for long-term control. Mice can breed quickly and replace any member previously trapped. If you can’t seal off openings immediately then try to place traps in these boundary zones until they are closed. By keeping all food in rodent tight containers you will minimize the chance that you will be subjected to a mouse infestation.
