Most of the leaping, twisting and flipping you see squirrels do has a purpose: getting through the treetops, dodging predators, or playing. Their bodies are built for all three, with a tail that steers in midair and signals to enemies on the ground, and feet that grip almost anything. Occasionally, though, a squirrel that keeps tipping over or flopping onto its side while otherwise calm is not showing off. That can point to brain illness.
The Random Flips Are Usually Play
A squirrel will often wander around the lawn looking relaxed, then abruptly start rolling, flipping, running in zigzags and jumping, with no visible trigger.1The Kid Should See This. Silly Squirrels: “Flipping, zipping, rolling, and going nuts for no good reason” These bursts are usually play. Squirrels play alone by running, climbing, jumping, twisting, tumbling and play-fighting with objects.2Wildlife Online. Squirrel Play Behaviour
Two or more squirrels can play together too, through mock fights, wrestling and chasing.3Wildlife Online. Squirrel Play Behaviour Social play even includes pretend courtship, with chasing and mounting that look like mating but aren’t.4Wildlife Online. Squirrel Play Behaviour
Play is widely thought to rehearse escape moves like sudden twists and zigzags. Young squirrels play the most, since they are still learning to move in trees, and practicing jumps and landings on the ground carries far less risk than doing it in the canopy. Play-fighting also builds coordination that comes in handy in real disputes over food. Young squirrels leaving the nest and exploring are the most likely to put on a show, so a sudden burst of tumbling in late spring or summer is often a youngster.
Telling play from the real thing is mostly a matter of rhythm. Play chases pause and restart, and the roles switch back and forth. Real territorial fights come with loud chattering, tail flicking and one squirrel clearly fleeing. Chases in spring and late winter are often real courtship rather than play.
A playing squirrel can look frantic yet keeps its footing between bursts. It pauses to look around, groom or nibble, then goes back to foraging as if nothing happened. If it recovers its balance every time, it is most likely a healthy animal letting off energy.
How Squirrels Leap Between Branches
Tree squirrels push off differently depending on what they’re standing on.5PubMed Central. Jumping performance in tree squirrels: Insights into primate evolution On flat ground they put most of their effort into raw pushing force. On a narrow branch they use a longer, more controlled push with the whole body.6PubMed Central. Jumping performance in tree squirrels: Insights into primate evolution
Before a long leap, a squirrel often freezes, bobs its head or shuffles its feet. This pause is planning, and it’s thought to help the squirrel judge the distance to the target. Moving the head back and forth shifts its viewpoint, which can help an animal estimate how far away something is.
The branch matters as much as the gap. A bendy branch absorbs some of the push and shortens the jump, so squirrels learn to launch from stiffer spots near the trunk. Landing on a thin end makes the branch dip, which is why they grab quickly. Squirrels learn which branches are sturdy and which gaps they can clear, so they use the same routes day after day.
When a jump goes wrong, squirrels fix it. One that jumps too far rolls forward around the branch.7University of California, Berkeley. Leaping Squirrels! Parkour Is One of Their Many Feats of Agility One that falls short catches the branch with its front legs, swings underneath, and pulls itself back on top.8University of California, Berkeley. Leaping Squirrels! Parkour Is One of Their Many Feats of Agility On tricky jumps, squirrels may bounce off a vertical surface like a wall or trunk to slow down for a better landing, much like human parkour.9University of California, Berkeley. Leaping Squirrels! Parkour Is One of Their Many Feats of Agility
Leaping and Tail Flicks to Dodge Predators
Ground squirrels living where snakes have recently been seen react faster to a strike and are more likely to leap straight up or sideways away from it.10Behavioral Ecology. The fear of unseen predators: ground squirrel tail flagging in the absence of snakes signals vigilance With no snake around, they rarely do these evasive leaps.11Behavioral Ecology. The fear of unseen predators: ground squirrel tail flagging in the absence of snakes signals vigilance They also wave their tails at the snake, and the more they wave, the faster they move away.12Behavioral Ecology. The fear of unseen predators: ground squirrel tail flagging in the absence of snakes signals vigilance The display tells a snake the squirrel is alert and ready to dodge, which discourages it from striking.13PubMed Central. Ground squirrel tail-flag displays alter both predatory strike and ambush site selection behaviours of rattlesnakes Tail waving by adult squirrels also makes snakes more likely to abandon their hiding spot.14PubMed Central. Ground squirrel tail-flag displays alter both predatory strike and ambush site selection behaviours of rattlesnakes
Tree squirrels flick their tails at cats, hawks, people and other squirrels, so a flick means “I have noticed you” more than “there is a snake.” A squirrel flicking its tail while staring at you has most likely noticed you and is wary.
A squirrel that has spotted danger often freezes first, with a stiff pose and wide alert eyes, before it decides whether to run. It then tends to bolt in zigzags toward a tree rather than in a straight line, which makes its path harder for a cat or hawk to predict.
How the Tail Turns a Fall Into a Landing
In an unexpected fall, squirrels spin their bent tails to slow the spin of their body, passing that spinning motion into the tail.15Integrative and Comparative Biology. Inertial Tail Effects during Righting of Squirrels in Unexpected Falls: From Behavior to Robotics Rotating the tail in a circle lets them keep spinning it continuously, instead of hitting limits as a simple up-down or side swing would.16Integrative and Comparative Biology. Inertial Tail Effects during Righting of Squirrels in Unexpected Falls: From Behavior to Robotics The same trick is being studied to help robots stay upright when they fall.17Integrative and Comparative Biology. Inertial Tail Effects during Righting of Squirrels in Unexpected Falls: From Behavior to Robotics
Cats right themselves mainly by twisting their very flexible spine, turning the front and back halves of the body in sequence. Squirrels add a large, fluffy tail that does much of the work, which is why a squirrel’s flip can look like a corkscrew with the tail whirling.
Sticking the Landing on a Narrow Branch
On landing, a squirrel’s front legs alone slow it by about two-thirds.18PubMed Central. Free-ranging squirrels perform stable, above-branch landings by balancing using leg force and nonprehensile foot torque Overall, the front legs absorb close to 90% of the landing energy, whatever the jump length.19PubMed Central. Free-ranging squirrels perform stable, above-branch landings by balancing using leg force and nonprehensile foot torque The force still climbs with distance: it more than doubles from about twice body weight on a 50 cm jump to over four times body weight on a 1 m jump.20PubMed Central. Free-ranging squirrels perform stable, above-branch landings by balancing using leg force and nonprehensile foot torque To stay balanced, squirrels twist their feet against the branch rather than gripping it like a hand.21PubMed Central. Free-ranging squirrels perform stable, above-branch landings by balancing using leg force and nonprehensile foot torque Robot designers are copying these landings to build machines that can hop between beams or tree limbs.22Science Robotics. A squirrel-inspired robot that can leap from limb to limb
If you watch closely, the front paws hit the branch first, with the body and back legs arriving a moment later. The body often dips and sways briefly before settling, as the legs soak up the impact.
Why Squirrels Can Run Down Trees Headfirst
Tree squirrels can turn their back feet completely around when coming down a tree headfirst.23Journal of Mammalogy. Squirrels: the animal answer guide Their very flexible back ankles can rotate about 180 degrees,24Sierra Magazine. Why Squirrels Are Nuts for Acrobatics so the curved back claws dig into the bark and act as brakes while descending.25Sierra Magazine. Why Squirrels Are Nuts for Acrobatics The foot turns with its sole on the trunk and toes pointing up.26Northeastern Naturalist. Functional Measurement of Hind-Foot Reversal in Family Sciuridae This comes from unusually wide movement at ordinary ankle and foot joints, not from a special extra joint.27PubMed. Mechanisms of hind foot reversal in climbing mammals Tree-dwelling squirrels can twist their feet much further than ground-living kinds.28Northeastern Naturalist. Functional Measurement of Hind-Foot Reversal in Family Sciuridae
Watch a squirrel coming down a trunk: its back toes point up while its head points down. It often pauses headfirst, hanging by its back claws, to look around.
When Flipping or Spinning Means a Squirrel Is Sick
Squirrels very rarely get rabies.29CWRA. Help An Adult Squirrel Some, however, are infected by a roundworm parasite that damages the brain.30CWRA. Help An Adult Squirrel An infected squirrel acts normally, then suddenly tilts or flops over, then acts normal again.31CWRA. Help An Adult Squirrel Stumbling, spinning in circles or seeming disoriented can be linked to brain parasites or viral infections.32Skedaddle Humane Wildlife Control. Zombie Squirrels: What You Need To Know Sadly, a squirrel with this roundworm infection doesn’t recover.33CWRA. Help An Adult Squirrel
Playful flips come in bursts, and the squirrel lands steadily and runs off. A sick squirrel may tilt or flop with no jump at all and struggle to right itself. Head tilting, walking in circles and falling off low perches are warning signs, especially if they repeat.
If a squirrel repeatedly falls over, circles, or can’t stay upright, call a local wildlife rehabilitator rather than handling it. Watch from a distance first and note what it does and for how long. Don’t feed, pick up or try to treat it yourself, and cover it with a box only if a rehabilitator advises it. Wash your hands and keep pets away from areas where a sick squirrel has been.
Why Flying Squirrels Pay More to Run
Flying squirrels use about 1.3 to 1.7 times more energy running than expected for their size.34PubMed. Quadrupedal locomotor performance in two species of arboreal squirrels: predicting energy savings of gliding Fox squirrels, close relatives of gray squirrels, use about the expected amount.35PubMed. Quadrupedal locomotor performance in two species of arboreal squirrels: predicting energy savings of gliding The reason is that the gliding membrane and climbing adaptations raise the cost of running on four legs by over 50%.36PubMed. Quadrupedal locomotor performance in two species of arboreal squirrels: predicting energy savings of gliding Flying squirrels make up for it by saving energy and time when they glide between feeding spots.37PubMed. Quadrupedal locomotor performance in two species of arboreal squirrels: predicting energy savings of gliding