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Roof Rat

Rattus rattus

Mammal · family Muridae · order Rodentia

  1. G1
    Critically imperiled
  2. G2
    Imperiled
  3. G3
    Vulnerable
  4. G4
    Apparently secure
  5. G5
    Secure

NatureServe global rank G5: secure[2].

Updated October 30, 2026. Published by Humblebee.

Endangered Species Act
Not listed[1]
NatureServe global rank
G5 Secure[2]
Longest recorded life
4.2 years[3]

The Roof Rat (Rattus rattus) is a rodent in the family Muridae, also called the Black Rat[4][5]. It is an introduced species in many US states and is not listed under the Endangered Species Act[6][1].

Conservation status

NatureServe gives the Roof Rat a global rank of G5, which it labels Secure[2]. The IUCN Red List category recorded by NatureServe is Least concern[7]. The animal is not listed as endangered or threatened under the US Endangered Species Act in USFWS data[1]. In every state where NatureServe gives a rank, the rank is SNA, since the animal is not native there[8][6].

Status Value
Endangered Species Act[1] Not listed
NatureServe global rank[2] G5 (Secure)
IUCN Red List (via NatureServe)[7] Least concern

Where Roof Rat lives

NatureServe lists the Roof Rat as introduced, not native, in 28 places: Alabama, Arkansas, Arizona, the District of Columbia, Delaware, Georgia, Illinois, Kansas, Louisiana, Massachusetts, Maryland, Missouri, Mississippi, North Carolina, New Jersey, New Mexico, Nevada, New York, Oklahoma, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Virginia, Washington and West Virginia[6][8]. Observation records on GBIF come most often from California, Florida, Texas, Hawaii and Louisiana[9]. Those counts follow where people look and report, not how many animals live there[9].

Alaska: not recordedAKMaine: not recordedMEWisconsin: not recordedWIVermont: not recordedVTNew Hampshire: not recordedNHWashington: introduced, state rank SNAWAIdaho: not recordedIDMontana: not recordedMTNorth Dakota: not recordedNDMinnesota: not recordedMNIllinois: introduced, state rank SNAILMichigan: not recordedMINew York: introduced, state rank SNANYMassachusetts: introduced, state rank SNAMAOregon: introduced, state rank SNAORNevada: introduced, state rank SNANVWyoming: not recordedWYSouth Dakota: not recordedSDIowa: not recordedIAIndiana: not recordedINOhio: not recordedOHPennsylvania: introduced, state rank SNAPANew Jersey: introduced, state rank SNANJConnecticut: not recordedCTRhode Island: introduced, state rank SNARICalifornia: not recordedCAUtah: introduced, state rank SNAUTColorado: not recordedCONebraska: not recordedNEMissouri: introduced, state rank SNAMOKentucky: not recordedKYWest Virginia: introduced, state rank SNAWVVirginia: introduced, state rank SNAVAMaryland: introduced, state rank SNAMDDelaware: introduced, state rank SNADEArizona: introduced, state rank SNAAZNew Mexico: introduced, state rank SNANMKansas: introduced, state rank SNAKSArkansas: introduced, state rank SNAARTennessee: introduced, state rank SNATNNorth Carolina: introduced, state rank SNANCSouth Carolina: not recordedSCDistrict of Columbia: introduced, state rank SNADCOklahoma: introduced, state rank SNAOKLouisiana: introduced, state rank SNALAMississippi: introduced, state rank SNAMSAlabama: introduced, state rank SNAALGeorgia: introduced, state rank SNAGAHawaii: not recordedHITexas: introduced, state rank SNATXFlorida: not recordedFLPuerto Rico: not recordedPR
State presence as recorded by NatureServe[8].
Show state ranks (28 states)
StateRankMeaning
AlabamaSNANot Applicable
ArizonaSNANot Applicable
ArkansasSNANot Applicable
DelawareSNANot Applicable
District of ColumbiaSNANot Applicable
GeorgiaSNANot Applicable
IllinoisSNANot Applicable
KansasSNANot Applicable
LouisianaSNANot Applicable
MarylandSNANot Applicable
MassachusettsSNANot Applicable
MississippiSNANot Applicable
MissouriSNANot Applicable
NevadaSNANot Applicable
New JerseySNANot Applicable
New MexicoSNANot Applicable
New YorkSNANot Applicable
North CarolinaSNANot Applicable
OklahomaSNANot Applicable
OregonSNANot Applicable
PennsylvaniaSNANot Applicable
Rhode IslandSNANot Applicable
TennesseeSNANot Applicable
TexasSNANot Applicable
UtahSNANot Applicable
VirginiaSNANot Applicable
WashingtonSNANot Applicable
West VirginiaSNANot Applicable

Habitat

NatureServe records many habitat types for the Roof Rat, including hardwood forest, hardwood woodland, cropland and hedgerows, suburbs and orchards, cities and buildings, and areas beside streams and rivers[10]. It is often found near people and often climbs in trees[11]. In some places it also lives in natural habitat[11]. Young are born in nests in sheltered spots, such as inside buildings or other cover[11].

Habitat types recorded by NatureServe[10]

Size, diet and lifespan

The Roof Rat eats a wide mix of plant and animal foods and is partial to grain[12]. One estimate of its diet is 40% seeds, 30% invertebrates, 20% fruit and 10% other plant material[13]. A typical adult is about 46 cm (18 in) long[14] and weighs about 350 g[15]. Females can start breeding at about 90 days old[16]. Pregnancy lasts about 22 days in AnAge data[17]. The oldest known Roof Rat in the AnAge database lived in captivity, and that is a record, not a typical lifespan[3].

Trait Value
Typical length[14] 46 cm (18 in)
Typical adult weight[15] 350 g (12.3 oz)
Longest recorded lifespan (AnAge)[3] 4.2 years (captivity)
Litter or clutch size[18] 7.3
Gestation or incubation[17] 22 days
Female maturity[16] 90 days (about 0.2 years)
Food habits[19] Carnivore, Invertivore, Herbivore, Granivore, Frugivore
Active[20] nocturnal
Migration[21] non-migrant

Estimated diet composition (EltonTraits 1.0)[13]

  • 40% seeds
  • 30% invertebrates
  • 20% fruit
  • 10% other plant material

When to look for it

The Roof Rat is nocturnal, which means it is active mostly at night[20][22]. NatureServe lists it as a non-migrant, though populations can differ[21]. It breeds throughout the year[23]. On GBIF, most US records fall in January, October and November[24]. Those records show when people look and report, not how many animals there are[24].

January: 636 recordsJanFebruary: 454 recordsFebMarch: 522 recordsMarApril: 529 recordsAprMay: 464 recordsMayJune: 462 recordsJunJuly: 499 recordsJulAugust: 528 recordsAugSeptember: 427 recordsSepOctober: 557 recordsOctNovember: 625 recordsNovDecember: 502 recordsDec
US observation records on GBIF by month, all years. The three months with the most records are highlighted. Records show when people look and report, not how many animals there are[24].
Show records by month
MonthRecords
January636
February454
March522
April529
May464
June462
July499
August528
September427
October557
November625
December502

Where to see it

National Park Service species lists record Roof Rat as present in 38 park units[25]. Present means the park has a confirmed record, not that sightings are common.

And 14 more park units.

States with the most GBIF observation records: California, Florida, Texas, Hawaii, Louisiana[9]. These counts follow where people look and report, not population size.

Questions people ask

Is the Roof Rat endangered?
No. It is not listed as endangered or threatened under the US Endangered Species Act[1]. NatureServe ranks it G5, which it labels Secure[2].
Where does the Roof Rat live in the US?
NatureServe lists it as introduced in states including Texas, Louisiana, Georgia, New York and Oregon[6]. GBIF records come most often from California, Florida, Texas, Hawaii and Louisiana[9].
What does the Roof Rat eat?
It is a very opportunistic feeder on plant and animal foods and is partial to grain[12]. One estimate is 40% seeds and 30% invertebrates[13].
How big is a Roof Rat?
A typical adult is about 46 cm (18 in) long[14] and weighs about 350 g[15].

Facts and sources

  1. Roof Rat is not listed as endangered or threatened under the US Endangered Species Act in USFWS ECOS data (checked 2026-10-30). USFWS ECOS
  2. NatureServe global conservation status rank for Roof Rat: G5 (Secure). NatureServe Explorer
  3. Maximum recorded lifespan in AnAge: 4.2 years in captivity. This is a record, not a typical lifespan. AnAge
  4. Roof Rat (Rattus rattus) is a mammal in the family Muridae, order Rodentia. NatureServe Explorer
  5. Other English names listed by NatureServe for Roof Rat: Black Rat, Rata Negra. NatureServe Explorer
  6. NatureServe lists Roof Rat as introduced (not native) in: Alabama, Arkansas, Arizona, the District of Columbia, Delaware, Georgia, Illinois, Kansas, Louisiana, Massachusetts, Maryland, Missouri, Mississippi, North Carolina, New Jersey, New Mexico, Nevada,... NatureServe Explorer
  7. IUCN Red List category as recorded by NatureServe: Least concern. NatureServe Explorer
  8. NatureServe state ranks for Roof Rat (map and table on this page). NatureServe Explorer
  9. US states with the most GBIF observation records of Roof Rat: California, Florida, Texas, Hawaii, Louisiana. Record counts follow observer effort, not population size. GBIF
  10. Habitat types NatureServe records for Roof Rat: Forest - hardwood, Woodland - hardwood, Cropland/hedgerow, Suburban/orchard, Urban/edificarian, Riparian. NatureServe Explorer
  11. NatureServe notes on habitat for Roof Rat. NatureServe Explorer
  12. NatureServe notes on food for Roof Rat. NatureServe Explorer
  13. Estimated diet composition in EltonTraits 1.0: 40% seeds, 30% invertebrates, 20% fruit, 10% other plant material. EltonTraits 1.0
  14. Typical length recorded by NatureServe: 46 cm (18 in). NatureServe Explorer
  15. Typical adult weight recorded by NatureServe: 350 g (12.3 oz). NatureServe Explorer
  16. Age at female sexual maturity in AnAge: 90 days (about 0.2 years). AnAge
  17. Gestation or incubation period in AnAge: 22 days. AnAge
  18. Typical litter or clutch size in AnAge: 7.3. AnAge
  19. Adult food habits recorded by NatureServe: Carnivore, Invertivore, Herbivore, Granivore, Frugivore. NatureServe Explorer
  20. Activity time in EltonTraits 1.0: nocturnal. EltonTraits 1.0
  21. NatureServe migration category for Roof Rat: non-migrant (populations can differ). NatureServe Explorer
  22. NatureServe notes on phenology for Roof Rat. NatureServe Explorer
  23. NatureServe notes on reproduction for Roof Rat. NatureServe Explorer
  24. GBIF observation records of Roof Rat in the US by month (chart on this page). GBIF
  25. NPSpecies park lists recording Roof Rat as present (list on this page). NPS NPSpecies

Status, range and habitat come from NatureServe Explorer (CC BY 4.0) and USFWS ECOS at the snapshot date. Listings change by federal rule. State lists are where NatureServe records the species, not a promise that you will see it there. Never name a place smaller than a state. GBIF and park records count observations and checklists. They show where and when people report the species, not how many animals live there.

NatureServe. 2026. NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org. (Accessed: October 30, 2026). Licensed under CC BY 4.0; SpeciesFacts selected and summarized it.