Shortly after the enactment of preventative measures aimed at limiting the spread of COVID-19, local governments and public health authorities around the world reported an increased sighting of rats. We combined multi-catch rodent station data, rodent bait stations data, and rodent-related residents’ complaints data to explore the effects that social distancing and lockdown measures might have had on the rodent population within the City of Sydney, Australia. We found that rodent captures, activity, and rodent related residents’ complaints increased during the COVID-19 related lockdown period, followed by a steep decline post-lockdown. We found no changes in the geographical distribution of any of our indices of rodent abundance. We hypothesize that lockdown measures resulted in an increase in rodent activity driven by a reduction in human-derived food resources. This might have increased the mortality rate triggering a population crash. There is a high chance that the surviving individuals might be rodenticide resistant. It is possible that the onset of COVID-19 might have disrupted commensal rodent populations, with profound implications for the future management of these species. Here we make available multi-catch rodent station data and rodent bait stations data. We do not include rodent-related residents’ complaints data due to potential identifier data that could be seen as a breach of private information sharing.

These data sets comprise:

Flick SMART Multi-Catch rodent station data set, obtained from 20 to 60 multi-catch rodent stations deployed across the council from October 2019 to July 2020. Deployment was non-random and guided by strategic pest management priority zoning. These stations were baited with barbeque grease and commercially available rodent attractants. The Council receives monthly reports from Flick Anticimex Pty Ltd that contained the number of traps active, their location in latitude and longitude coordinates, and the number of captures per day per each trap.

Rodent bait stations (PROTECTA EVO Ambush and PROTECTA LP, Bell Laboratories, Inc.) data set, obtained from 940 stations deployed across the council of the city of Sydney from September 2019 to August 2020. Deployment was non-random and guided by strategic pest management priority zoning. These stations were baited with commercial poisoned baits (Bromadiolone: Contrac Blox and Contrac Soft Bait; Brodifacoum: Ditrac Blox; Difethialone: Generation Block and Rodilon Soft Block; Flocoumafen: Storm Secure Block and Storm Soft Bait). Baits were randomly rotated at each station, to prevent rodents from developing an aversion to any bait. Each station was checked regularly (mean: 10.56 Days ± SE: 0.06) and scored according to the rodent activity i.e. low: no bait consumed and no visual signs; or high: bait consumed and visual signs present. Following strategic pest management, a bait station with consistent low activity scores was relocated. The location for all bait stations was recorded in UTM coordinates to facilitate spatial analyses.

Overall_Smart_Box_data.csv file:

This file comprises Flick SMART Multi-Catch rodent station data. It contains 10 columns and  9456 rows, with the first row composed of headings defined as follows:

• Day: value from 1 to 305 representing the period of time in days from Flick SMART Multi-Catch rodent station deployment (October 1st, 2019; Day 1), to the last day of data collection used for analysis (July 31st, 2020; Day 305).
• DATE: Calendar date corresponding to the data acquisition for the corresponding data point.
• LOCATION: General description of the location where the corresponding data point was acquired. This is in street name format
• Lat: Geographical coordinates referring to the Latitude where the corresponding data point was acquired.
• Long: Geographical coordinates referring to the Longitude where the corresponding data point was acquired.
• LockdownLvl: integer value from 0 to 6 representing the different levels of social distancing measures enforced by the Australian and New South Wales government during COVID-19 pandemic.
• HardLockdown: binary value from 0 to 1 representing the hard lockdown of restaurants and food retailers enforced by the Australian and New South Wales government during COVID-19 pandemic.
• Period: Categorical variable based on "HardLockdown", representing the temporal progression before, during, and after closures of restaurants and food retailers enforced by the Australian and New South Wales government during COVID-19 pandemic.
• Traps: integer value corresponding to the number of Flick SMART Multi-Catch rodent stations active at the corresponding location and the time of the data acquisition. These data were used as a measure of trapping effort.
• Captures: integer value corresponding to the number of rats captured at the corresponding location. NA represents missing data, due to no traps been active at the time of assessment. 

Bait_station_data.csv file:

This file comprises bait rodent station activity data. It contains 11 columns and  12503 rows, with the first row composed of headings defined as follows:

• DAY: value from 1 to 345 representing the period of time in days from bait rodent station deployment (Septemeber 2nd, 2019; Day 1), to the last day of data collection used for analysis (August 11tht, 2020; Day 345).
• Date: Calendar date corresponding to the data acquisition for the corresponding data point.
• MBP_ID2: Coded confer to each bait station and location combination.
• feat_cent_east: Geographical coordinates referring to the UTM easting where the corresponding data point was acquired.
• feat_cent_north: Geographical coordinates referring to the UTM northing where the corresponding data point was acquired.
• Activity: Categorical score (High or Low) given by pest manager contractors during an inspection of bait stations. NA represents bait stations that were not assessed.
• ActivityBi: Coverts activity score into a binomial values between 0 =Low and 1 = High.
• Bait type: Description of the bait deployed at each bait station.
• LockdownLvl: integer value from 0 to 6 representing the different levels of social distancing measures enforced by the Australian and New South Wales government during COVID-19 pandemic.
• HardLockdown: binary value from 0 to 1 representing the hard lockdown of restaurants and food retailers enforced by the Australian and New South Wales government during COVID-19 pandemic.
• Period: Categorical variable based on "HardLockdown", representing the temporal progression before, during, and after closures of restaurants and food retailers enforced by the Australian and New South Wales government during COVID-19 pandemic.

Bait_station_data2.csv file:

This file comprises summarized bait rodent station activity data. It contains 7 columns and  244 rows, with the first row composed of headings defined as follows:

• DAY: value from 1 to 345 representing the period of time in days from bait rodent station deployment (Septemeber 2nd, 2019; Day 1), to the last day of data collection used for analysis (August 11tht, 2020; Day 345).
• Date: Calendar date corresponding to the data acquisition for the corresponding data point.
• AStations: Integer value denoting the number of bait stations active at the corresponding time of the data acquisition. These data were used as a measure of trapping effort.
• ActivitySocre: The total sum of activity score (see file above) for all the active bait stations assess at the corresponding time of data acquisition. 
• LockdownLvl: integer value from 0 to 6 representing the different levels of social distancing measures enforced by the Australian and New South Wales government during COVID-19 pandemic.
• HardLockdown: binary value from 0 to 1 representing the hard lockdown of restaurants and food retailers enforced by the Australian and New South Wales government during COVID-19 pandemic.
• Period: Categorical variable based on "HardLockdown", representing the temporal progression before, during, and after closures of restaurants and food retailers enforced by the Australian and New South Wales government during COVID-19 pandemic.