Rodent Alert during Covid-19 Lockdown

Article by: Dr Gerhard H Verdoorn, Griffon Poison Information Centre +27-82-446-8946.

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The global Covid-19 pandemic caught the entire world by surprize and forced many nations to go into lockdown mode to curb the spread of the highly contagious virus. Being confined to one’s own place of residence is best for personal protection, but it has unforeseen consequences for public health, especially for people living in highly confined spaces. Some of these consequences may arise from the very large population of brown rats (also known as the ship rat Rattus norvegicus) that has literally taken over urban neighbourhoods.


The British Pest Control Association (BPCA) did a poll in April and found that 51% of pest professionals reported an increase in rat activity, while 41% reported an increase in mice activity during the timeline of restrictions. They noted that empty buildings, deserted streets and reduced footfall provide a perfect opportunity for rodents to flourish across the UK, with rats and mice seemingly becoming bolder, braver and more innovative in finding food and shelter in the shutdown. The situation in South Africa is much the same*.


Brown rats are highly commensal with human habitation and flourish in residential areas and informal settlements. Concerned pest specialists have been warning for years that South Africa is heading for a disaster because of the rat infestation with disturbing news from hospitals and the Griffon Poison Information Centre that people are often attacked by rats at night while sleeping. Rats nibble on fingers, ear lobes and exposed feet of adults and children. This situation is of grave concern because rats and their associated fleas may carry Yersinia pestis bacteria that cause bubonic and pneumonic plague. They also transmit Salmonella bacteria that cause various gastric ailments while they are also probably responsible for the spread of Esherichia coli that cause severe gastric ailments and Staphyloccus aureus that cause respiratory tract infections and dermatitis in human beings. Studies in other countries proved that rats often carry antibiotic resistant strains of these bacteria. If these bacteria are established in human beings, it may be a bad or even worse than the Corona virus that has the world in its tight grip.


Video footage seen by the Griffon Poison Information Centre of a nocturnal scene in township close to Johannesburg is reason for serious concern. Brown rats scurry around people in their hundreds and cash in on refuse and food waste that is left in garbage dumps all around the township. Reports from residents in Pretoria and the greater Johannesburg Metropolitan area are also alarming; rats are running around during daytime in homes, gardens and in playgrounds and shopping centres. Refuse removal needs to be improved because it a haven for rats and other harmful creatures.


With the strong and very necessary focus on quarantine against the Covid-19 pandemic, South Africans must not lose sight of the public health threat posed by the brown rat population. It is very important to control rats continuously to avert a bubonic plague outbreak which the country can ill afford in these trying times. Rodenticides are available for rodent control but Bayer Environmental Health stresses the importance of placing baits only in bait stations where it is inaccessible to dogs and children. This is not negotiable because ingestion of any rodenticide by a dog or a child may be very serious or fatal at worst.


Pest control operators are advised to only use registered rodenticides, follow label instructions, and to always use bait stations. It is strongly advisable to collect dead rats on the fourth to seventh days after putting out rodenticide baits; this is required as a sanitation measure especially during the quarantine period. Rats normally expire within four to seven days after eating most rodenticides but in areas of high infestation and continuous baiting, there will always be dead and dying rodents. Sanitation is very important to prevent secondary disease outbreaks.


You are invited to call the Griffon Poison Information Centre on 082-446-8946 for advice of which rodenticides to use in which situations because every situation demands an analysis of the human situation, environmental situation and level of rat infestation. It is very important to not create a risk for people, their pets and the natural environment in which owls play a very important role in suppressing rodent populations.


*Source: The British Pest Control Association (BPCA) Covid-19 impact study (20 April 2020) as quoted in the article “Surge in pest activity in Covid-19 shutdown” on