Rat Week

Rat and Mice Destruction Act in Holborn

Written by Katie Egger

On January 1st, 1920, London enacted the Rats and Mice [Destruction] Act and as a result of the anti-rat sentiments, and ways to control rat populations were presented in the British Medical Journal. Analyzing the rat destruction measures in India, F. Norman White determined the most important measure in the war against the rats would be the knowledge of rat habits. The “rat-proofing” of establishments in London would prevent the accessibility to rats of food, water, and the sewers. In terms of eradication, the setting of traps with barium carbonate, which was determined to be the most effective poison, were measures he suggested be enforced in the boroughs.

Prior to the introduction of Rat Week, buildings suspected to harbor rats were inspected and instructed in rat elimination if rats were found on the premises. Holborn, an inner borough of London, enacted measures in 1919 beginning the development of rat destruction measures through the inception of the inaugural “Rat Week,” which was thence forth held towards the beginning of each November. Rat Week was introduced for the purpose of encouraging concerted efforts in the borough to enact anti-rat measures and control the urban rat population. In both 1919 and 1920, Rat Week was held but not to the degree seen in later years. Beginning in 1921, Rat Week propaganda began to be distributed throughout the borough. Circulars and leaflets were delivered to promote the importance of rat elimination and the concept of rat-proofing was introduced. There was also a Rat Week film, titled “Kill That Rat”, played in the cinema during the week. These propaganda regimes continued through 1929.

From the focus on concerted effort, came new policies. In 1921, legislation was proposed to the Public Health Committee and Council which included preparations of rat poisons for purchase at cost price, Work and General Purposes Committee workmen being available for rat proofing measures at the expense of the property owner, and the establishment of a firm of rat catchers. These policies were enacted the following year by the council and were continued throughout the decade analyzed. The arrangement of the firm of rat catchers and the council was proved useful until 1927 in which the emergence of privately employed rat catchers threatened the success of the arrangement. What made the arrangement successful was the requirement of the rat catchers to share the information concerning the status of the premises with the council, thereby allowing the council to forewarn neighboring premises. This issue had not been resolved by 1929. Other regimes organized by the council included quadrupling the number of traps laid during a normal week for Rat Week. Baiting for the traps included barium carbonate, discussed by Mr. White as being the most effective, and “dalroc” which was a liquid preparation of red squill used to soak stale bread. The baiting alone was not enough to eliminate the rats and this led to the introduction of legislation with the intention of “rat proofing” Holborn.

During 1921, it was proposed to the Ministry of Health, the Ministry of Agriculture and Fisheries, and the London County Council that owners of properties with disused drains should notify the Local Sanitary Authority of the drains thereby placing the liability on the owners. This proposal was approved the following year. In 1923, regarding disused drains, it was decided that the owners of properties should not be held financially responsible for the sealing or removal of disused drains. The clause was agreed upon and in 1926 it was included in the London County Council Bill and titled “Disused Drains”. The same year that the Disused Drain clause was proposed, a memorandum was issued on the topic of rat proofing. According to the memorandum the two most common rats in the borough were the brown [house] rats and the black [ship] rats. Brown rats localized in the sewers, entering homes from unused drains, while the black rat’s capability to climb allowed it scale houses and enter through chimneys, windows, and roof ventilators. The proposals addressed covering and filling any holes or openings the rats could gain access through and then focused on preventing the rats already in the premises from gaining access to food and water.

Many of these “rat-proofing” suggestions came from information shared at a conference over the topic of rat control held in Holborn in 1922 during Rat Week. Mr. E C Read emphasized the importance of limiting the rat’s ability to travel through the sewers. Dr. W. M. Willoughby emphasized that the most important thing was not only removing rats from the sewers and forcing them above ground but also limiting their food source. He claimed that the undisturbed nesting and access to food had been what allowed the rat population to proliferate despite baiting with poison. These concerns as well as the understanding of rat habits and behaviors were the basis for the rat-proofing procedures.

At this same conference, Mr. E C Read informed the attendees of the responsibility placed on Britain to maintain the defenses against rats year round due to its trade with the rest of the world. Many years after in other countries, the persistence of rats can still be seen and the measures they took against the rat populations increased in creativity. Maui, Hawaii, in 1937, acted against their native and foreign rat species after the second plague outbreak in 1931, with the first having been in 1900. Not yet having the knowledge of the superior effectiveness of sanitary procedures, Maui used poisoning to kill the rat population. Unfortunately, due to the large food stores resulting from Maui’s lush terrain and agricultural production, the rats were not pressured to take the bait and the poisoning was not effective. Efforts to eradicate typhus fever, caused by fleas on rats, were taken between the years of 1945 to 1957 in Southwestern Georgia, USA. Dusting of rat runs with DDT, and later the combined DDT application and anticoagulant rat poisons in rural areas, were used to control and eradicate flea species on the rats, who also perished. The study, in contrast to the anti-rat sentiments during the 1920’s in London, focused not on eradicating rats, but controlling commensal populations. In urban America in 1969, the failed methods for rat eradication included poisoning, fumigation of burrows, trapping, and chemosterilants. At this same time in the UK there was evidence arising of Warfarin-resistant rat populations. Due to this the UK was forced to constantly monitor populations of resistant rats to prevent outward migration. The US saw the danger of this resistant population and moved to implement environmental sanitation which had been successful in Norway.

Rat Week was the foundation for many rat-elimination techniques and for the method of using sanitary measures to limit the rat’s access to food, water, and undisturbed burrows. While the policies developed through trial and error arose most quickly in London, many other countries used similar methods of rat elimination. The concerted efforts in London as emphasized during Rat Week is a direct analogy to the concerted efforts of nations over time to share knowledge and techniques to control the rat populations worldwide.


Holborn 1919

Rat and Mice Destruction Act of 1919

White, F. Norman. “Rat Destruction.” The British Medical Journal 2, no. 3072 (1919): 629-30.

Holborn 1920

Holborn 1921

Holborn 1922

Rat Control.” The British Medical Journal 2, no. 3230 (1922): 1041.

Holborn 1923

Holborn 1924

Holborn 1925

Holborn 1926

Holborn 1927

Holborn 1928

Holborn 1929

Rat-Hunting In Hawaii.” The British Medical Journal 1, no. 3972 (1937): 395-96.

Love, G. J., and W. W. Smith. “Murine Typhus Investigations in Southwestern Georgia: A Review.” Public Health Reports (1896-1970) 75, no. 5 (1960): 429-40.

James M. Clinton. “Rats in Urban America.” Public Health Reports (1896-1970) 84, no. 1 (1969): 1-7.

Regional Differences in Rat Week During the Year 1937

Written by Michelle McKinney

In the Medical Officer of Health reports from 1919 to 1964, an event called Rat Week is mentioned in reports from multiple boroughs. Rat Week was established by the Rats and Mice (Destruction) Act of 1919, and the week involved a borough-wide effort to reduce the number of rats in private and public property.  In order to gain a greater understanding of how Rat Week differed by borough, the Medical Officer of Health reports from multiple boroughs written in 1937 will be examined. Although Rat Week seems drastic, there were many factors that contributed to its prevalence during the 20th century.

Rats fighting; the plague spreading.
Rats fighting; the plague spreading. Drawing by A.L. Tarter, circa 1940. Image Credit: Wellcome Library, London.

Historically many factors shaped the public’s opinion of rats. Two religious philosophies influenced views towards animals. The first philosophy, anthropocentrism, stated that human beings were God’s focus and that all other animals were created to serve humans, which means that anything humans did to animals was justified (Velten 9). Anthropocentric views were also supplemented by the Great Chain of Being, which was a hierarchical order of all living beings, with angels and humans at the top, and all other living thing things below that (9). Both of these philosophies combined to justify the mistreatment of animals, especially rats. Additionally, some scholars thought that rat corpses polluted the air, which facilitated the spread of disease (Cole 30). By the time rats were associated with the plague baccilus in 1898, the public opinion of rats was already very negative; rats were also associated with typhus, salmonella, leptospirosis, and rat-bite fevers (“Embodied Wildlife Histories” 447). Even outside of their capabilities to cause disease, rats wreaked havoc by damaging property, contaminating food, and biting people (In the crevices of the city 38).

In 1919, the Rats and Mice (Destruction) Act was passed. According to the Act, if there were rice or mice on a property then the “occupier” of the “land” must take precautions that were “necessary and reasonable practicable” in order to prevent the property from becoming infested with rats or mice (Rats and Mice). In the context of the act, an occupier was the tenant, a resident, or the land’s owner. Land was defined as any “buildings or other erection on land,” including cellars, sewers, drain, or culverts (Rats and Mice).  If the occupier did not take necessary precautions, then a small fine could be incurred. The Act also states that “a local authority” has the power to “give instructions as to the most effective methods that can be adopted” in their area in order to destroy the rats and mice (Rats and Mice). The Medical Officers of Health seem to be the local authorities entrusted with educating the public on rats and mice under the Rats and Mice Destruction Act.

According to the Medical Officer of Health reports from 1937, Rat Week seemed to have a set structure. For instance, in the Dagenham report, the medical officer wrote that, “The same procedure operated during the year as in the past in connection with rats and mice” (Dagenham 38). It seems that in 1937, many boroughs had a similar formula for Rat Week. Generally, there was a concerted propaganda effort. Traps or poison were deployed during Rat Week in the sewers and private properties if complaints about rats were received. In some boroughs, the number of rat corpses and sprung traps were counted. Additionally, free rat poison was distributed in some boroughs. Out of the eleven Medical Officer of Health reports from 1937 examined for this page, all boroughs but Kingston upon Thames had a Rat Week. The medical officer expressed that while no official Rat Week was held “activity in connection with this important matter” occurred throughout the year (Kingston upon Thames 57).  In contrast, the boroughs of Stepney and Shoreditch cooperated to hold multiple Rat Weeks in 1937 in order to eliminate rats in the sewers.

Although the other boroughs held Rat Weeks, they had different methods of raising awareness of Rat Week in the community. One main feature of many of the different Rat Weeks was propaganda. Most boroughs displayed some sort of poster in order to promote Rat Week. Another method of promoting Rat Week involved distributing information about how to successfully exterminate rats throughout the borough. This method was employed by Stepney, Chingford, Marylebone, and Finsbury. In Marylebone, residents were given a pamphlet called “Rats and how to exterminate them” and encouraged to join the “organized attack” (Marylebone 48). While the Maryleborne pamphlet was oddly warlike, the information distributed in Finsbury had a much different tone. According to the MOH report, Finsbury was also focused on the prevention of further infestations, and advised residents to properly store food items and keep their properties “clear of debris (Finsbury 91). Despite a focus on prevention, the leaflets distributed in Finsbury also included information about the “proper laying of rat poison” and rat catchers “of good reputation” (91). Two boroughs, Stepney and Chigwell, showed notices about Rat Week in local cinemas. Because it was present in so many boroughs, propaganda seems to have been a cornerstone of rat week.

Regardless, some Medical Officers of Health disagreed with the role propaganda and publicity played in Rat Week. After noting the public’s “indifferent support” of Rat Week, the MOH in Barking stated that “the only real propaganda is efficient service” (85). The MOH from Chingford also expressed that interest in Rat Week appeared to be “exceedingly small” and that it was, “…difficult to assess the real value, if any, of this form of propaganda” (Chingford 23). In Shoreditch, the MOH said that residents of Shoreditch did not realize that, “… the Rats and Mice (Destruction) Act, 1919, places upon the owner the onus of clearing rat-infested premises” (Shoreditch 135). Despite the number of Medical Officers of Health that expressed doubt about rat week, the Medical Officer of Health from Chigwell wrote that  “no undue increase of signs of rat infestation” were present in the borough (Chigwell 14). Therefore, the success of Rat Week seemed highly dependent on each borough.

A rat caught in a trap; victim to man's efforts to stem the spread of plague
A rat caught in a trap; victim to man’s efforts to stem the spread of plague. Drawing by A.L. Tarter, circa 1940. Credit: Wellcome Library, London.

Another way Rat Week differed from borough to borough was the rat destruction method used. Although most boroughs used some type of poison, other boroughs made specific notes of the rat deterrents used. Stepney specifically mentioned using Rodine, barium carbonate, phosphor paste, and “extract of squills” (Stepney 40). Marylebone used “”break-back” traps that had “particular value” and rat infestations decreased in the sewers when “repair or reconstruction was carried out” (Marylebone 47). In Wandsworth, rat catchers used dogs and ferrets as well as bait. Dagenham used unspecified poison, smoke, and gas. In Chigwell, the rat population was destroyed by “gassing by means of Cyano Gas Pump” and “baiting with Red Squill bait” (Chigwell 14). The Chigwell Medical Officer of Health also noted that the bait was not successful because of “the rats having access to food” (14). Although most of the boroughs shared a general procedure for rat week, the boroughs used different rat control methods.

Despite all of the similarities between Rat Weeks in the different boroughs, it seems that each borough had its own consensus about what aspects of Rat Week were effective, which included opinions about propaganda, baits, and whether Rat Week itself was even effective.


Barking 1937

Biehler, D. “Embodied Wildlife Histories and the Urban Landscape.” Environmental History 16, no. 3 (2011): 445-50. doi:10.1093/envhis/emr048.

Biehler, D. (2007). In the crevices of the city: Public health, urban housing, and the creatures we call pests, 1900–2000 (Order No. 3294117). Available from ProQuest Dissertations & Theses Global. (304769455).

Chigwell 1937

Chingford 1937

Cole, Lucinda. “Rats, Witches, Miasma, and Early Modern Theories of Contagion.” In Imperfect Creatures: Vermin, Literature, and the Sciences of Life, 1600-1740, 24-48. Ann Arbor: University of Michigan Press, 2016.

Dagenham 1937

Finsbury 1937

Kingston upon Thames 1937

Marylebone 1937

Rats and Mice (Destruction) Act, 1919

Shoreditch 1937

Stepney 1937

Velten, Hannah. Beastly London: A History of Animals in the City. Chicago, IL: Reaktion Books, 2013.

Wandsworth 1937