General public
- How many rodent species are there?
There are three common species of commensal rodents in Hong Kong, namely Rattus norvegicus (sewer rat), Rattus rattus (roof rat) and Mus musculus (house mouse). - What diseases do rodents transmit?
Rodents transmit a number of diseases such as plague, urban typhus, scrub typhus, spotted fever, leptospirosis and hantavirus infection. - How to confirm if there is rodent infestation in residential premises?
Rodents are nocturnal creatures and generally not often seen during daytime. However, rodent activities will leave some traces (signs). By observing these signs, we can confirm whether there is rodent infestation in the place. Common signs of rodent activities include rodent droppings, rat holes, gnawing marks, smears, etc. - How to handle rodent infestation in residential premises?
If rodent infestation is found in residential premises, the relevant property management company should be notified for assistance or a pest control company should be appointed for disinfestation. Do not try to catch rodents yourself. For enquiries, members of the public can contact 1823, the FEHD enquiry hotline at 2868 0000 or the FEHD District Environmental Hygiene Office concerned (during office hours). - How to dispose of dead rodents found in residential premises?
Wear plastic gloves (and a surgical mask, if necessary) before handling a dead rodent. Use tools such as tongs to put the dead rodent into a tough plastic bag. Wet the dead rodent thoroughly with general household disinfectant or diluted bleaching solution. Seal the plastic bag and put it into another plastic bag. Then seal the outer plastic bag. Dispose of the plastic bags containing the dead rodent properly in a dustbin with cover or at a nearby refuse collection point.
Please click the link below for more details
https://www.fehd.hksarg/english/pestcontrol/library/pdf_pest_control/trapDead_rodent_e.pdf - How to handle trapped live rodents in cage traps?
Members of the public can contact 1823, the FEHD enquiry hotline at 2868 0000 or the FEHD District Environmental Hygiene Office concerned (during office hours) for collection of live rodents caught inside residential premises.
Private or public residential buildings with the appointment of property management companies should engage a pest control company to handle the live rodents caught in common parts of the buildings.
Please click the link below for more details
https://www.fehd.hksarg/english/pestcontrol/library/pdf_pest_control/trapDead_rodent_e.pdf
Rodent control operators
- Is poisonous baiting more effective than trapping?
Both poisonous baiting and trapping are effective methods for direct rodent control, and the choice between the two methods depends on the situations. For example, the use of traps can be considered where the use of poisonous baits is not suitable. As for handling heavy rodent infestation, it will be more effective to use poisonous baits. It should be noted that the use of poisonous baits and traps cannot tackle the problem at the root and only has a temporary effect on rodent control. The most effective solution in the long run is to eliminate the fundamental survival conditions of rodents in the environment, namely food, harbourage and passages. - What food should be used as baits for trapping?
Rodents are omnivorous. Their food preference varies from time to time and place to place. In choosing the baits for trapping, one can target at the food preference of different rodent species. Moreover, a mixed baits approach can be used. Food baits tested and proved to give better results are as follows:
Rattus norvegicus (sewer rat) – bacon, peanut (groundnut) butter, sweet potatoes, fresh fish, smoked or dried fish, ground meat, bread
Rattus rattus (roof rat) – nuts, meat, apples, carrots, bread
Mus musculus (house mouse) – cereal grains and seeds
Trials on different food baits should be conducted for any trapping operations at individual locations to find out the preferred combination of food baits. Moreover, fresh baits should be used as far as possible. Baits that have dried out or spoiled should be replaced immediately by fresh ones. - How to use rodent traps for effective trapping?
For effective trapping, a rodent survey is needed to ascertain the harbourage and dispersal routes of rodents. Based on the result of the survey, as many traps as possible and practicable should be laid. It is suggested that at least six traps should be laid for one or two rodents. For a trapping programme, the traps should be laid for at least five consecutive days and inspected once to twice daily. In addition, they must be baited with food and placed properly as detailed in Q(2) and Q(4). - How should rodent traps be placed?
Rodent traps should be placed close to the walls/vertical surfaces in rodent runways or areas where rodents frequent. When a snap trap/cage trap is used, the trigger of the snap trap/the opening (door) of the cage trap should be facing the wall/vertical surface. If snap traps/cage traps are set parallel to the wall/vertical surface, they must be set in pairs, with the triggers of the pair of snap traps/openings of the pair of cage traps facing out to intercept rodents coming from either direction. The traps should be set firmly on ground and should remain in the same position throughout each trapping period. Traps for mice should be placed 1 metre apart, and traps for rats should be placed 1 to 2 metres apart. - Should glue traps be used in rodent control?
When countering heavy rodent infestation where other rodent control methods have been exhausted without satisfactory results, glue traps may be considered as a tool to supplement the rodent control programme. However, operators should avoid to set glue traps outdoors or at areas with possible appearance/activities of other non-target animals (e.g. birds, cats and reptiles). Where necessary, glue traps should be enclosed in lockable, tamper-resistant bait stations or dedicated rodent glue trap tunnels to avoid capturing non-target animals. In addition, frequent inspections should be arranged to promptly collect the trapped rodents and kill them in a humane manner. - Which is the most effective in rodent control, cage traps, snap traps or glue traps?
If used correctly, all cage traps, snap traps and glue traps can capture rodents and facilitate rodent disinfestation, and the results are immediately evident. Suitable rodent traps should be chosen according to different situations. Cage traps can capture live rodents and are generally safer, and they can prevent other pest-related problems arising from ectoparasites leaving the bodies of rodents. Snap traps can kill rodents immediately but are more suitable to be used in concealed places that are not accessible to non-target animals (including humans). Glue traps are easy to use but should not be placed outdoors or at areas with possible activities of other non-target animals (e.g. birds, cats and reptiles). Moreover, frequent inspections should be arranged to promptly collect the trapped rodents and kill them in a humane manner. - How to choose suitable rodenticides?
When choosing rodenticides, in addition to whether their active ingredients and dosage can effectively eliminate rodents, due consideration should also be given to the safeness of the rodenticides. The active ingredient of most of the rodenticides available in the market is anticoagulant. Although a delayed action occurs (a rodent will normally die several days after ingestion of a lethal dose), it has a higher safety level as well as different formulations for use in different environments. The product labels should be carefully studied before use and the rodenticides should be applied according to the recommended dosage and methods. All rodenticides used should have been registered with the Agriculture, Fisheries and Conservation Department, and their product labels should bear the relevant registration numbers
