Rodent Complaints in Baltimore: Where and When (2023–2026 311 Data)
By Marcus Ellery, Pest Control Editor · Updated September 2026 · Methodology
Baltimore logged 6,020 rodent complaints in 2025, which was down 10.9% on 2024, and 5,395 so far in 2026 through September. The year peaks in August at about 11.63% of annual volume and bottoms out in December at 5.42%. The busiest ZIP codes over the three full years were 21213, 21224, 21218, 21217, 21216, and 21213 alone ran about 675.8 complaints per square mile.
What Baltimore counts
Resident-initiated requests for city action on rats: Baltimore’s "SW-Rat Rubout" and follow-up requests plus Housing’s "HCD-Rodents" requests. Baltimore also logs a much larger volume of "SW-Rat Rubout Proactive" records, which are baiting runs the Department of Public Works schedules itself rather than anything a resident reported. Those are excluded here, because counting them would make the city’s work calendar look like rodent activity.
Pulled from Open Baltimore — 311 Customer Service Requests (dataset 311_Customer_Service_Requests) with the filter SRType IN ('SW-Rat Rubout','SW-Rat Rubout Follow-up','SW-Rat Rubout Alley Concern (SW creation only)','HCD-Rodents') [excludes SW-Rat Rubout Proactive]. 100% of records carry a ZIP code. This is a different definition from the other cities we publish, so these counts should never be set against theirs.
Complaints by month, 2023 to 2026
September, October and November are shaded so you can see how the autumn months sit against the rest of the year in Baltimore.
2023
Year total 7,391
2024
Year total 6,757
2025
Year total 6,020
2026 (through Sep)
Year total 5,395
One caveat about the Baltimore data
Baltimore needs one substantial caveat. Its 311 system logs a category called "SW-Rat Rubout Proactive", which is baiting the Department of Public Works schedules on its own initiative, and it outnumbers actual resident requests by roughly twenty to one. Counting it would turn a chart of the city's work calendar into what looks like a chart of rodent activity. Everything below excludes it and covers only requests somebody actually filed: Rat Rubout, its follow-ups, and Housing's rodent cases.
Reading the Baltimore numbers
Baltimore spreads its rodent complaints across 29 ZIP codes, and the load is not spread evenly. The busiest five carry 45% of the three-year total and the busiest ten carry 73%. ZIP 21213 alone logged 2,319 complaints, about 3.9 times the median ZIP code in the city. Adjusting for size changes the picture: 21217 runs the densest at about 707 complaints per square mile across 2.12 square miles, even though it sits at rank 4 on raw volume.
Across the year, August (11.63%), October (10.98%) and July (10.96%) are the three heaviest months, while December (5.42%), January (5.66%) and February (6.08%) are the three lightest. May through October alone accounts for roughly 62% of a Baltimore year. Year to year the totals ran -8.6% into 2024, then -10.9% into 2025. 2026 stands at 5,395 through September.
Baltimore also records what the complaint was about. In 2025, 64% of them came in as “SW-Rat Rubout” (3,867 of 6,020), which is worth knowing before you read the total as a rodent count.
Every month, in full
The raw counts behind the charts above, so you can check our arithmetic against Open Baltimore — 311 Customer Service Requests yourself.
| Month | 2023 | 2024 | 2025 | 2026 | Avg share |
|---|---|---|---|---|---|
| January | 565 | 346 | 254 | 404 | 5.66% |
| February | 490 | 401 | 341 | 326 | 6.08% |
| March | 556 | 499 | 485 | 614 | 7.65% |
| April | 575 | 651 | 65 | 696 | 6.16% |
| May | 724 | 627 | 185 | 785 | 7.38% |
| June | 754 | 567 | 680 | 815 | 9.96% |
| July | 724 | 752 | 720 | 889 | 10.96% |
| August | 767 | 765 | 794 | 719 | 11.63% |
| September | 618 | 665 | 883 | 147 | 10.96% |
| October | 742 | 659 | 792 | — | 10.98% |
| November | 526 | 476 | 439 | — | 7.15% |
| December | 350 | 349 | 382 | — | 5.42% |
Average share is the mean of each full calendar year’s monthly share, so a heavy year cannot dominate the seasonal curve. The 2026 column is incomplete by design.
The 25 busiest ZIP codes in Baltimore
Totals cover 2023 through 2025, the three full calendar years in the window. Per square mile uses the Census ZCTA land area, which is what makes a small dense ZIP comparable to a large one.
| Rank | ZIP | 2023–2025 total | Per sq mi |
|---|---|---|---|
| 1 | 21213 | 2,319 | 675.8 |
| 2 | 21224 | 2,302 | 246.8 |
| 3 | 21218 | 1,630 | 376.5 |
| 4 | 21217 | 1,499 | 707 |
| 5 | 21216 | 1,307 | 395.8 |
| 6 | 21229 | 1,291 | 217.5 |
| 7 | 21215 | 1,284 | 188.5 |
| 8 | 21230 | 1,107 | 175.2 |
| 9 | 21239 | 967 | 330 |
| 10 | 21223 | 931 | 354.6 |
| 11 | 21206 | 872 | 120.2 |
| 12 | 21212 | 666 | 145.2 |
| 13 | 21225 | 609 | 94.3 |
| 14 | 21202 | 597 | 369.5 |
| 15 | 21205 | 581 | 283.2 |
| 16 | 21214 | 438 | 156.7 |
| 17 | 21211 | 433 | 151 |
| 18 | 21231 | 365 | 420.8 |
| 19 | 21201 | 360 | 283.6 |
| 20 | 21234 | 160 | 12 |
| 21 | 21226 | 127 | 13 |
| 22 | 21222 | 118 | 10.3 |
| 23 | 21207 | 73 | 7.1 |
| 24 | 21209 | 47 | 7.3 |
| 25 | 21210 | 37 | 10.7 |
29 ZIP codes recorded at least one complaint. Volume tracks reporting behaviour as well as rodent activity: a block that knows how to use 311 shows up more than an identical block that does not.
What kind of complaint (2025)
Baltimore records a sub-type on each complaint, which separates an actual sighting from a report about conditions.
| SW-Rat Rubout | 3,867 | 64.2% |
| HCD-Rodents | 2,062 | 34.3% |
| SW-Rat Rubout Follow-up | 90 | 1.5% |
| SW-Rat Rubout Alley Concern (SW creation only) | 1 | 0.0% |
Freeze dates for Baltimore
The nearest NOAA station publishing 1991–2020 first-freeze normals is MD SCI CTR BALTIMORE, 1.3 miles from the city point. One autumn in ten sees its first 32°F night by November 7; a typical year gets one around November 21; nine years in ten have had one by December 8. The station averages 52 nights a year below freezing.
We went into this expecting complaints to climb toward the first freeze. In Baltimore they do not. Baltimore complaints peak in August, and by November the month carries 3.81 percentage points less of the year than September did, with the typical first freeze still landing in November. We publish the gap rather than smoothing it. The likeliest reason is that a 311 rodent complaint is mostly an outdoor rat report, and outdoor rat activity runs highest in warm weather, while the autumn move indoors is house mouse behaviour that rarely becomes a city service request. Somebody with mice behind a kitchen cabinet calls an exterminator, not the city.
What removal costs if it is your house
National 2026 planning ranges from our estimator, not Baltimore quotes.
| Inspection + trapping | $175 – $500 |
| Removal + exclusion (seal entry points) | $400 – $1,100 |
| Above + attic cleanup / decontamination | $700 – $2,000 |
Check a Baltimore ZIP
Complaint total and rank inside Baltimore, plus freeze dates for the nearest station.
Frequently asked questions
Which Baltimore ZIP codes have the most rat complaints?
Over 2023 to 2025, the busiest ZIP codes were 21213 (2,319), 21224 (2,302), 21218 (1,630), 21217 (1,499), 21216 (1,307). Ranking by complaints per square mile changes the order, because a large ZIP collects more calls simply by being large. Both columns are in the table above. A busy ZIP code reflects how often people there call 311, which is not the same as how many rodents live there.
When do rodent complaints peak in Baltimore?
August, which carries about 11.63% of the year's complaints against 5.42% in December, the quietest month. That is roughly 2.1 times the volume between the high and low month. Autumn is already past the peak: November carries 3.81 points less of the year than September does.
What exactly does Baltimore count as a rodent complaint?
Resident-initiated requests for city action on rats: Baltimore’s "SW-Rat Rubout" and follow-up requests plus Housing’s "HCD-Rodents" requests. Baltimore also logs a much larger volume of "SW-Rat Rubout Proactive" records, which are baiting runs the Department of Public Works schedules itself rather than anything a resident reported. Those are excluded here, because counting them would make the city’s work calendar look like rodent activity. We pulled it from Open Baltimore — 311 Customer Service Requests using the filter SRType IN ('SW-Rat Rubout','SW-Rat Rubout Follow-up','SW-Rat Rubout Alley Concern (SW creation only)','HCD-Rodents') [excludes SW-Rat Rubout Proactive]. Nearly every record carries a ZIP code, so the ZIP code table and the citywide totals agree closely.
Are rodent complaints rising in Baltimore?
Between 2023 and 2025 they went down, by -18.5%. Year over year, 2025 was down 10.9% against 2024. Complaint counts move when a city promotes its 311 line or changes a category, so read the direction as a signal about reporting as much as about rodents.
Does the Baltimore complaint peak match the first freeze?
No, and the mismatch is the interesting part. The typical first 32°F night at MD SCI CTR BALTIMORE lands in November, but Baltimore complaints peak in August and are already falling by November. We checked this across all six cities we pull and the pattern held in every one of them, so we are not going to tell you 311 data proves a rodent season that starts at the first freeze. City 311 rodent complaints are dominated by outdoor rat activity, which runs highest in warm months. The autumn move indoors is mostly a house mouse story, and a mouse in your wall rarely generates a call to the city.
Sources
- Open Baltimore — 311 Customer Service Requests — dataset 311_Customer_Service_Requests, filtered on
SRType IN ('SW-Rat Rubout','SW-Rat Rubout Follow-up','SW-Rat Rubout Alley Concern (SW creation only)','HCD-Rodents') [excludes SW-Rat Rubout Proactive], extracted September 9, 2026. - NOAA NCEI U.S. Climate Normals 1991–2020 — station USW00093784, MD SCI CTR BALTIMORE.
- U.S. Census Bureau 2023 ZCTA gazetteer — ZIP land area used for the per-square-mile column.
- UC Statewide IPM Program — Pest Notes: Rats (Publication 74106) — rat behaviour and exclusion.
Getting a quote in Baltimore
Run the estimator for a fair range, then get two or three written quotes from licensed operators.
Free, no obligation. PestCost may be compensated by licensed pest control providers who receive your call or quote request. This never changes what you pay.
PestCost is an independent cost-information site, not a pest-control company, and does not service Baltimore. We may be compensated by licensed providers who receive your call or quote request. This never changes what you pay. Complaint counts describe what residents reported to Baltimore, not a count of rodents.