Pennsylvania mammals

House Mouse in Pennsylvania

Mus musculus

Introduced to Pennsylvania

Pennsylvania's Mus musculus records are of an introduced species; it does not occur here as a wild native population.

IUCN Red List status

  1. LC
  2. NT
  3. VU
  4. EN
  5. CR
  6. EW
  7. EX

LC – Least Concern

Widespread and abundant; not at risk.

House Mouse in Pennsylvania, by the numbers

Occasional in Pennsylvania 29th most recorded of 77 mammals logged in Pennsylvania

254 occurrence records
179 with iNaturalist photos

Records from 2000–2026.

254 total records count every Pennsylvania occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 248; the monthly chart covers the 247 records with a full observation date.

When to look for the House Mouse in Pennsylvania

Most sightings fall in July to August.

247 Pennsylvania occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence.

Monthly Pennsylvania records (table)
MonthRecords
January12
February9
March16
April20
May20
June21
July42
August28
September24
October27
November19
December9

Monthly house mouse occurrence records (iNaturalist and GBIF) in Pennsylvania, 2000–2026.

Seasonality

Year-round in Pennsylvania, with recorded sightings peaking in July–August, with a smaller rise in October.

Occurrence map

Where House Mouse has been recorded in Pennsylvania

248 records mapped · zoom and drag to explore

248 Pennsylvania records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
State Game Land #46 1

Protected places with the most house mouse sightings, from the USGS Protected Areas Database plus named mountain ranges, good spots to look, not a full breakdown, so they don't sum to the total.

Where it's recorded in Pennsylvania

CountyRecords
Philadelphia County 95
Allegheny County 33
Bucks County 21
Montgomery County 19
Delaware County 10
Lancaster County 7
Northampton County 7
Lehigh County 6
McKean County 6
Berks County 5
Adams County 4
Cumberland County 4
16 other counties 37

The complete county distribution, spread across 28 Pennsylvania counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

House-mouse records in Pennsylvania parks describe human-used space more than wild habitat. Buildings, campgrounds, and storage areas at Pymatuning and Presque Isle provide food and shelter, while developed pockets repeat that pattern along the much larger Delaware Water Gap corridor.

Records rise in July and August as summer visitation increases discoveries around facilities. They track encounters where people concentrate resources, not the size of local mouse populations.

Occurrence data from iNaturalist and GBIF.

House Mouse in other states

More mammals in Pennsylvania in the atlas

Data & sources

The data and visualizations on this page draw on these open sources:

  • GBIFCC-BY 4.0occurrence records behind the range map, elevation, and record counts
  • iNaturalistCC0 / CC-BY / CC-BY-SAobservations, photos, and audio recordings
  • NatureServe ExplorerCC-BYthe state conservation rank
  • IUCN Red Listattributed factthe global conservation status
  • USGS NASpublic domainnative / introduced status
  • Natural Earthpublic domainthe relief basemap
  • USFSpublic domainnational-forest boundaries
  • USGS Protected Areas Databasepublic domainthe named parks, forests, and refuges behind "notable places to look"