As someone who grew up in New York City (Queens), I found this dataset from NYC Open Data on rat sightings to be very interesting. I wanted to take a look at the data and share a few visualizations. This subject has been treated by a few others, my favorite can be found here. I hope to give a fresh look at it, but some points will inevitably be repeated.
Data Set + A Map
You can take a detailed look at the data on the NYC Open Data site. Each row is a sighting with meta data in the columns. There are quite a few columns of data, but not all of them are categorical or of any real interest to me. In my visualizations, I focus on the geographic data as well location type of the reported rat sighting. This data is from 2010-March 2016. It should be noted that not all data points are confirmed rat sightings. Some are tagged as rodent sightings or mouse sightings but for the purpose of this blog I’ll just treat them as equals. To get an overall look, here is a map created with CartoDB:
Here is a scatter plot chart of the data. It’s perhaps a bit disconcerting that the number of rat sightings are increasing overtime. This is most likely the case because it’s easier to report rat sightings now than in 2010 with the proliferation of smart phones. I haven’t lived in NYC in some time, but the fight against rats has been going on for as I can remember. As a side note, Rats have become somewhat iconic in internet culture with “Pizza Rat” and “Save your drunk friend rat”
Brooklyn has the most sightings, as the most populated borough there are likely to be more rats and more sightings. Staten Island, being isolated from the rest of NY has the least. Queens has far fewer than I would have expected. Not sure I should be proud of hundreds or rats reported as sighted within a year though.
By Location Type
Perhaps unsurprisingly, 3+ Family apartment buildings are the most common places where rat sightings are reported. A large portion of housing, especially in Brooklyn is of this type. Fortunately, schools are among the least frequently reported. I noticed restaurants aren’t on this list, which is probably better. We need not know which restaurants had rats reported there.
By Day Of Week
There are likely some irregularities with how the data is reported and inputted and thus the beginning of the week has the most entires and the weekend the fewest. Nonetheless, it’s still interesting to think of rats flooding NYC during the time when people are at work and out and about the most and getting caught carrying slices of Pizza down the stairs.
I would love to see a similar dataset for other cities. New York is so unique, but large city living isn’t uncommon in the U.S.. Seeing this data for San Franciso or Atlanta would be interesting too! Kudos to everyone who reports and thanks to NYC for collecting the data.
 NYC Data and Jeremy Singer-Vine for the data
 CartoDB for making some of their platform available for free
 Thanks to Max Woolf for ggplot2 themes and tips