Why Are Squirrels' Tails Fluffy? Five Jobs at Once

The tail is a balance pole, a parachute, a blanket, a sunshade and a signal flag. Why the hair is loose rather than dense, and what a thin tail means.

By Zakaria November 2, 2026 3 min read Save to Pinterest

A grey squirrel on grass with its tail raised in a full silvered plume — Photo: JonPauling, Pixabay Content License, via Pixabay

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The tail is fluffy because surface area is the point. Long, loosely packed hair spreads into a wide, light fan — and a fan is what a counterweight, a parachute, a blanket, a parasol and a signalling flag all need.

The short answer

A squirrel's tail hair is long and loosely packed rather than dense because every one of its jobs needs surface area: a counterweight for balance on branches, an air brake and partial parachute in a fall, a blanket wrapped over the body in cold, a parasol held over the back in heat, and a visible flag for signalling. Dense fur would insulate better but spread less. The skin and hair also detach readily, so a predator that grabs the tail is left holding fur while the squirrel escapes.

Surface area, not insulation — that is why it is loose and long
Balance: a counterweight for every turn on a branch
Falls: an air brake, and they survive long drops
Thermal: blanket in winter, parasol and heat dump in summer
Signal: tail flicks are the main visible squirrel-to-squirrel message

The five jobs

job	how the fluff helps
Balance	a wide, light mass swung to counter shifts in the centre of gravity
Falling	spread hair adds drag; squirrels survive falls that should injure them
Warmth	wrapped over the back and head at rest, it traps a layer of still air
Cooling	arched over the body as shade; blood flow through it dumps heat
Signalling	a big visible flag that reads clearly at distance

Dense, plush fur — a mole’s, say — would insulate better per gram. It would also be heavy, narrow and useless as a counterweight or a flag. The loose arrangement is a compromise that serves five purposes adequately rather than one perfectly.

Balance is the primary one

Watch a squirrel run a fence rail and the tail is never still. Every change of direction is preceded and accompanied by a tail movement in the opposite sense, which keeps the combined centre of mass over the rail.

It matters most in the places squirrels actually live: twig-thin branch ends, wires, gutters and roof edges, where a mistake is a long fall.

Why the falls do not kill them

A spread tail adds drag, a squirrel’s low body weight means a low terminal velocity, and the loose splayed posture they adopt spreads the impact. Squirrels routinely survive falls from heights that would badly injure a heavier animal.

The thermal pair

Cold: the tail comes forward over the back and head, and the squirrel curls under it. In a drey, with two or three animals sharing, this is a real part of how they get through a northern winter without hibernating
Heat: the tail arches over the back as shade, and blood flow through it increases so heat is lost from the skin. A squirrel splooting flat on cool concrete with its tail up is doing both at once

The flag

Tail flicks are the most visible thing a squirrel does, and they are aimed:

At a predator — “I have seen you”, which makes stalking pointless
At other squirrels — alarm, or a territorial warning
At a rival at a feeder or over a cache

A squirrel flicking its tail at you has made a decision about you.

When the tail looks wrong

appearance	likely cause
Sparse and uneven for a few weeks	moult — happens twice a year
Thin tail and thin, crusted body coat	mange mites
Short stump, healed	old injury or an escape from a predator
Bare, dark, dried section at the tip	degloving injury, the skin lost and the rest drying

The detachable skin is deliberate. A hawk or a cat that closes on the tail ends up with a handful of fur sleeve and no squirrel, and the exposed bone dries and drops off. It costs the animal balance and both thermal functions, and plenty of three-quarter-tailed squirrels live out normal lives anyway.

A squirrel that is thin in the body, slow, and losing coat over the back as well as the tail is a different matter — that is a case for a licensed wildlife rehabilitator, not for home treatment.

Common questions

Why are squirrels' tails so fluffy?

Because loose, long hair does five jobs that dense fur cannot. Spread out, the tail works as a counterweight when the squirrel runs along a branch, as an air brake and partial parachute in a fall, as a blanket wrapped over the body in cold, as a sunshade held over the back in heat, and as a visible signalling flag. Each of those needs surface area rather than insulation, which is why the hair is long and loosely packed instead of thick and plush.

What is a squirrel's tail actually for?

Balance first. A squirrel running a branch or a fence rail swings the tail to counter every shift in its centre of mass, which is what lets it change direction at speed on a surface an inch wide. After that it is thermal — wrapped over the body at rest in winter, held over the back as shade in summer — and then communication, since tail flicks are the main visible signal squirrels give each other.

Can a squirrel survive losing its tail?

Yes, and partial tail loss is common. The skin and hair of the tail detach fairly easily, which is an escape adaptation: a predator left holding a sheath of fur has not caught a squirrel. The exposed bone usually dries and falls away. A squirrel with a stump balances noticeably less well and loses the blanket and parasol functions, but plenty live normal lives.

Why does my squirrel's tail look thin or ratty?

Usually moult, which happens twice a year and makes the tail look sparse and uneven for a few weeks. The other common causes are mange from a mite infestation, which also thins the body coat and leaves bare grey skin, and a healed injury. A squirrel that is thin in the body as well as the tail, with crusted skin, is a candidate for a call to a wildlife rehabilitator rather than something to treat yourself.

Do squirrels use their tails as umbrellas?

They hold the tail arched over the back in rain and in strong sun, and it sheds a useful amount of both. It is not a dry shelter — a squirrel in heavy rain goes to its drey — but for a shower or for midday heat the arched tail measurably reduces what reaches the body. In heat the tail also helps dump heat, since blood flow through it can be increased to shed warmth.

Why do squirrels flick their tails?

It is a signal, and a deliberate one. A flicking tail tells an approaching predator that it has been spotted, which removes the point of an ambush, and it warns other squirrels nearby. Squirrels also flick at each other in territorial disputes and around food. It is not a nervous tic, and a squirrel flicking at you has classified you as a threat rather than scenery.

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