Look-Alike Animals comparison

Rat vs Squirrel: Key Differences Explained

The short answer

Both are rodents, but they sit in different families and the tail settles most sightings. A squirrel belongs to Sciuridae and carries a broad, bushy, plumed tail used for balance, shade and signalling, and tree squirrels feed in daylight. A rat belongs to the genus Rattus in Muridae and has a long, thin, scaly, sparsely haired tail, with brown rats active mainly around dusk and through the night. Posture helps as well: squirrels sit upright with the tail arched, while rats forage low with the body held horizontal.

The main difference

A squirrel's tail is broad, bushy and plumed and it feeds in daylight; a rat's tail is thin and scaly and it moves mostly after dark.

These are the two rodents people most often glimpse in gardens and parks, and a grey-brown body vanishing into cover is genuinely ambiguous for a second or two. Tail shape, time of day and the way each animal moves resolve almost every such sighting without needing a close view.

At a glance

Comparison of Rat and Squirrel across 6 dimensions, with an interpretation of each difference.
What differs	Rat	Squirrel	What it means
Family	Genus Rattus in Muridae, the Old World rats and mice	Family Sciuridae, spanning tree squirrels, ground squirrels, chipmunks, marmots and flying squirrels	One name points at a single genus while the other covers a whole family, so a squirrel sighting always needs a second question about which kind.
Tail	Long, scaly and sparsely haired, roughly head-and-body length in the brown rat and longer in the black rat	Broad and bushy with a plumed outline, held arched over the back at rest or flicked while calling	The tail reads at a distance and in poor light, which makes it the most dependable field mark this pair offers.
Activity period	Brown rats are mainly crepuscular and nocturnal, though daytime sightings happen where food is abundant	Tree squirrels are diurnal, with foraging peaks in the morning and again in late afternoon	Time of day is a strong prior: a bushy-tailed rodent crossing a lawn at noon is very unlikely to be a rat.Flying squirrels are nocturnal, so the daylight rule applies to tree and ground squirrels rather than to the family as a whole.
Movement	Runs and scurries with the body low along walls and banks; brown rats climb competently and swim well	Travels in arched bounds and descends tree trunks head-first by rotating the hind ankles	Head-first descent of a vertical trunk is a squirrel trait, and no rat performs it in the same way.
Food and storage	Opportunist taking grain, fruit, seeds, invertebrates, eggs and discarded human food, hoarded in larders	Mostly seeds, nuts, buds, flowers, fungi and bark, with many species scatter-hoarding single items	Scatter-hoarding gives squirrels a documented role in tree regeneration that larder-hoarding rats do not fill.
Eyes	Small dark eyes with limited acuity, backed by long whiskers and an acute nose	Large eyes set high on the head, giving wide coverage for an animal active in daylight	Eye size tracks activity period so closely that it settles the identification in a photograph even when the tail is hidden.

Family: RatGenus Rattus in Muridae, the Old World rats and mice
SquirrelFamily Sciuridae, spanning tree squirrels, ground squirrels, chipmunks, marmots and flying squirrels
One name points at a single genus while the other covers a whole family, so a squirrel sighting always needs a second question about which kind.
Tail: RatLong, scaly and sparsely haired, roughly head-and-body length in the brown rat and longer in the black rat
SquirrelBroad and bushy with a plumed outline, held arched over the back at rest or flicked while calling
The tail reads at a distance and in poor light, which makes it the most dependable field mark this pair offers.
Activity period: RatBrown rats are mainly crepuscular and nocturnal, though daytime sightings happen where food is abundant
SquirrelTree squirrels are diurnal, with foraging peaks in the morning and again in late afternoon
Time of day is a strong prior: a bushy-tailed rodent crossing a lawn at noon is very unlikely to be a rat.Flying squirrels are nocturnal, so the daylight rule applies to tree and ground squirrels rather than to the family as a whole.
Movement: RatRuns and scurries with the body low along walls and banks; brown rats climb competently and swim well
SquirrelTravels in arched bounds and descends tree trunks head-first by rotating the hind ankles
Head-first descent of a vertical trunk is a squirrel trait, and no rat performs it in the same way.
Food and storage: RatOpportunist taking grain, fruit, seeds, invertebrates, eggs and discarded human food, hoarded in larders
SquirrelMostly seeds, nuts, buds, flowers, fungi and bark, with many species scatter-hoarding single items
Scatter-hoarding gives squirrels a documented role in tree regeneration that larder-hoarding rats do not fill.
Eyes: RatSmall dark eyes with limited acuity, backed by long whiskers and an acute nose
SquirrelLarge eyes set high on the head, giving wide coverage for an animal active in daylight
Eye size tracks activity period so closely that it settles the identification in a photograph even when the tail is hidden.

How they are related

Both are rodents, but from lineages that parted early in the order's history. Rats are murids: genus Rattus, family Muridae, within the mouse-related suborder Myomorpha. Squirrels are sciurids, family Sciuridae, within the squirrel-related suborder Sciuromorpha, a family that also holds ground squirrels, chipmunks, marmots and the nocturnal flying squirrels. Sharing gnawing teeth is an order-level trait rather than evidence that any particular rat and any particular squirrel are near relatives.

A note on naming: Rat here means the genus Rattus, with the brown rat, Rattus norvegicus, as the reference animal and the black rat, Rattus rattus, noted where it differs. Squirrel is a family-level name covering Sciuridae, so statements about tails, activity and diet describe typical tree squirrels rather than every member of that family.

Telling them apart

Look at the tail first. A squirrel's is broad, bushy and plumed, arched over the back at rest or flicked while the animal calls. A rat's is thin, scaly, sparsely haired and trailed out behind. Then check the eyes, since a tree squirrel's are large and set high on the head while a rat's are small and beady. Ear shape helps too: several squirrels carry conspicuous or tufted ears, while a rat's are low, rounded and thinly furred.

Bushy plumed tail, daylight, upright posture with food held in the forepaws: squirrel. Thin scaly tail, dusk or darkness, body low and horizontal: rat. If it ran head-first down a tree trunk, it was a squirrel, because the hind ankles rotate to allow that grip. If it swam across a ditch without hesitation and carried on, a brown rat is much the more likely candidate of the two.

Habitat and distribution

Tree squirrels need trees or something that works like them, nesting in cavities or in leafy dreys built high in a fork, while ground squirrels use open country and burrow systems instead. Brown rats favour ground level and below, working along banks, hedge bottoms, waterways and the margins of buildings, and black rats prefer higher and drier situations including roof spaces. Gardens and parks can hold both, which is precisely why the confusion arises.

Diet and ecological role

Squirrels concentrate on seeds, nuts, tree buds, flowers, fungi and bark, and many species scatter-hoard surplus in shallow caches relocated later by memory and smell, with forgotten caches helping trees regenerate. Rats are opportunists taking grain, fruit, seeds, invertebrates, eggs and discarded human food, and they gather stores into larders rather than dispersing single items. Both visit bird feeders, which is where the two are most often seen and mistaken for one another.

Behaviour

Tree squirrels are conspicuous and noisy, chattering and tail-flicking at anything that concerns them, and they forage openly in daylight. Rats are famously cautious about new objects in familiar places, and they do most of their moving in darkness along established routes close to cover. A rodent that freezes in the open and then bounds away with a plumed tail streaming behind it is a squirrel; one that hugs a wall and disappears without pausing is a rat.

Senses and adaptations

The squirrel's large, high-set eyes give broad coverage for a diurnal animal watching for movement from above, and the bushy tail doubles as a counterbalance in leaps, a parasol in heat and a blanket in cold. The rat's equipment suits darkness instead: long mobile whiskers sweep surfaces continuously, olfaction is acute, and hearing extends well into ultrasound. Neither set is superior in the abstract, since each matches when and where its owner is active.

More on this topic: Animal senses and adaptations.

Lifespan and life stages

Wild rats are short-lived, with most brown rats not reaching a year and few reaching two, because predation and disease press hard on a fast-breeding animal. Tree squirrels also suffer heavy losses in the first year, but individuals that reach adulthood often live several years and older wild animals have been recorded. Both are documented living longer under protection, and captive records should never be read as ordinary wild expectations for either.

People and these animals

Both live comfortably alongside people and both attract strong opinions. Squirrels are fed in parks in some countries and resented in others, particularly where introduced species have displaced native ones. Rats have travelled with human shipping for millennia and are now among the most widespread mammals on earth as well as among the most studied. This page covers their natural history and deliberately leaves aside control, removal and property questions.

What they have in common

Both are rodents with a single pair of ever-growing incisors in each jaw and no canine teeth.
Both climb well and both use trees, fences and wires as travel routes above the ground.
Both are adaptable enough to persist in towns, parks and gardens alongside people.
Both carry food away from where they find it and store it rather than eating everything on the spot.

Key differences

A squirrel's tail is bushy and plumed; a rat's is scaly and thinly haired.
Tree squirrels feed by day, while brown rats move mostly at dusk and through the night.
Squirrels scatter-hoard single items across an area; rats concentrate stores into larders.
A squirrel's eyes are large and set high on the head; a rat's are small and low.
Squirrel covers an entire family, whereas rat here means one genus within Muridae.

Where people go wrong

Treating any grey-brown rodent glimpsed in a garden as a rat without checking whether the tail was furred.
Assuming squirrel names a single animal, when the family spans tree, ground, flying and marmot-type rodents.
Expecting every squirrel to be active in daylight, which does not hold for the nocturnal flying squirrels.

Frequently asked questions

Is a squirrel just a rat with a fluffy tail?

No. They belong to different rodent families and different suborders, and the differences run past the tail into eye size, activity period, gait and food storage. A squirrel scatter-hoards single seeds across a wide area and feeds by day; a rat gathers stores into a larder and moves mostly after dark. The tail is simply the difference that is easiest to see from across a garden.

How do I tell a young squirrel from an adult rat?

A juvenile squirrel already has a furred tail, even before it becomes fully plumed, and its head and eyes look large for its body. It is usually seen in daylight, near or on a tree, and it moves in bounds. An adult rat has a bare scaly tail at every age, a proportionally smaller eye, and it travels along the ground with the body low. Time of day alone often settles it.

Are rats and squirrels closely related?

They are both rodents, which means both carry a single pair of ever-growing incisors in each jaw, but they sit in different suborders whose lineages separated deep in the order's history. Rats are murids in Myomorpha and squirrels are sciurids in Sciuromorpha. Being fellow rodents makes them roughly as related as two long-diverged branches of one large group, not close cousins.

Do rats and squirrels compete for the same food?

There is overlap, especially at bird feeders and around fallen fruit and nuts, but the emphasis differs. Squirrels concentrate on seeds, nuts, buds, fungi and bark, while rats take a far broader omnivorous range that includes invertebrates and human food waste. Overlap at a single food source does not mean two animals occupy the same ecological position across the year.

Why do I see squirrels in the daytime but almost never rats?

Because tree squirrels are diurnal and brown rats are mostly crepuscular and nocturnal. A squirrel is doing its ordinary business at midday, so it is visible. A rat is usually moving at dusk, at night, or under cover, and it prefers routes with edges and shadow. Daytime rat sightings do occur, particularly where food is concentrated, so the rule is a useful prior rather than an absolute.

Read the full profiles

Sources and methodology

How this comparison is built: FaunaHub comparisons are assembled from the sourced animal profiles behind them rather than written as standalone claims. Figures such as size, mass, and lifespan are typical ranges that vary by subspecies, population, region, sex, age, and — where relevant — whether an animal lives in the wild or under human care, so they are presented as ranges rather than fixed values. Where a common name covers a group rather than a single species, the page says so instead of implying a species-to-species match. Conservation status changes over time and should be confirmed against the current IUCN Red List. Dimensions that could not be supported from the underlying profiles are omitted rather than filled in.

What this page does not do: it does not rank the two animals, predict the outcome of a confrontation, or present either one as stronger, smarter, or better. It is not veterinary, medical, first-aid, handling, capture, hunting, or pest-control guidance. For an animal in your care, or any situation involving injury, contact a qualified veterinarian, your local wildlife authority, or emergency services.

Sources and further reading

Authoritative references used for general educational context. External links open in a new tab. These sources do not endorse FaunaHub.

UniversityAnimal Diversity Web — Rattus norvegicus (brown rat) — University of Michigan species account
UniversityAnimal Diversity Web — Rattus rattus (black rat) — University of Michigan species account
ReferenceEncyclopaedia Britannica — Animals reference — Editor-reviewed encyclopedia overview entries
Wildlife referenceIUCN Red List of Threatened Species — Authoritative source for current conservation status
UniversityAnimal Diversity Web — Sciurus vulgaris (Eurasian red squirrel) — University of Michigan species account
ReferenceBritannica — Squirrel — Editor-reviewed encyclopedia entry
UniversityAnimal Diversity Web — University of Michigan Museum of Zoology — Peer-edited reference accounts for animal species
Wildlife referenceSmithsonian's National Zoo & Conservation Biology Institute — Animals — Educational species pages from the Smithsonian Institution

Last updated: 2026-08-04