Why could scientists see a spiderling’s retinas moving?

Its skin is see-through for a while

They used a microscope inside the eye

House Jumping Spider

Pseudeuophrys lanigera

The house jumping spider (Pseudeuophrys lanigera) is a tiny jumping spider, 3–5 mm long, that lives mostly on and inside buildings in western and southern Europe. Like all jumping spiders (family Salticidae), it hunts by sight instead of with a web, using two big front eyes and six smaller ones. It has spread north and east with people’s houses and has now been found in North America too.

House jumping spider abilities

Leg 3 main jumping legs in this species
The house jumping spider leaps onto prey or across gaps. Filmed at high speed, it pushes off mainly with its long third legs, and its hairy feet grip even smooth surfaces.
- In this species the short fourth legs leave the ground first, so the long third legs do most of the work.
- Claw tufts on the feet stop it slipping. Without them, the spiders slipped as they tried to jump.
- How far jumping spiders jump varies a lot. Some species manage 2–3 body lengths, and one spider of the species Colonus puerperus was measured at 38 body lengths.
- In a lab study, a regal jumping spider jumped low and flat over short gaps and higher over gaps of up to 5 body lengths.
Sources [2, 5, 12]
1 line tied on before the jump
Before it jumps, a jumping spider glues a silk dragline to the spot it is standing on. The line is more than a safety rope: it steadies the spider in the air.
- If the jump fails, the spider climbs back up its dragline.
- In the jumping spider Hasarius adansoni, spiders with a dragline could change their body angle in mid-air and land smoothly.
- The silk slowed the jump about as much as air resistance did. Without it, spiders tended to tumble on landing.
- We found no study of the dragline in the house jumping spider itself, but jumping spiders in general use one.
Sources [2, 11]
≈360° field of view from 8 eyes
Eight eyes in four pairs let a jumping spider see almost all the way around. The side eyes spot movement and the big front eyes study the detail.
- The side eyes have wide views and are very sensitive to movement. When something moves, the spider turns to face it.
- The big front eyes see a narrow area in sharper detail than any other land invertebrate, better than all insects and even some mammals.
- Their brain is roughly the size of a poppy seed, yet it handles all this information.
Sources [1, 3, 4]
4 layers in each big-eye retina
The lenses of the big front eyes are fixed to the body, but the retinas behind them swing around inside. The spider looks around without moving its head.
- Each retina is a narrow, boomerang-shaped strip. Moving it scans an object bit by bit, the way we move our eyes.
- The retina has four stacked layers of light cells. In one jumping spider, the second-deepest layer always gets a blurry picture, and the amount of blur seems to tell the spider how far away prey is.
- In newly hatched spiderlings the skin is see-through for a while, so scientists could watch the retinas moving.
- These studies were done on other jumping spiders. The house jumping spider has the same kind of eyes.
Sources [1, 13, 14, 15]
3 kinds of drum signal (Habronattus)
Male jumping spiders court females with dances: front legs raised and waved, palps flicking, sometimes with vibrations too. Their displays are some of the most elaborate of any spiders.
- In the zebra spider, the male waves his front legs and palps and bobs his abdomen up and down.
- One American jumping spider, Habronattus dossenus, adds vibrations to its dance: thumps, scrapes and buzzes.
- In Maevia inclemens, one type of male dances on tiptoe from about 9 cm away, while another creeps up to about 3 cm.
- Nobody seems to have described the house jumping spider’s own dance in detail yet.
Sources [8, 16, 17, 18]
No extensors muscles at the leg’s hinge jointsStill debated
Spiders bend their legs with muscles but straighten them mostly with pressure. Squeezing body fluid into the legs makes them shoot straight, a bit like a water-filled balloon.
- Spider leg hinge joints have no muscles to straighten them. Pressure in the body fluid does that job.
- A clue: the leg spines stand up during a jump, a sign of higher body pressure.
- How much of the jump comes from pressure is still argued. A study of one regal jumping spider found its leg muscles were strong enough on their own, and a 2025 study describes jumps as pressure plus muscle.
- Engineers copy the folding joints to build soft robot legs.
Sources [6, 12, 16, 19]
Every night rests in a silk shelter
Jumping spiders hunt by day. At night and in bad weather they tuck into small silk tents, often in a crack or corner.
- The tent is a small silk bag, sometimes with an egg sac inside.
- Resting jumping spiders at night showed regular bursts of retinal movement with leg twitches. Scientists think this may be a sleep state a bit like our dreaming sleep, but it is not yet proven.
- Indoors, the house jumping spider is active all year. Adults can be found even in deep winter.
Sources [2, 7, 9, 15]
4 steps spot, turn, stalk, pounce
A jumping spider spots movement, turns to look, creeps closer and then leaps. The house jumping spider has been seen eating booklice, tiny insects that live indoors.
- Jumping spiders are daytime hunters. They track and stalk prey and judge the distance before they leap.
- When close enough, the spider pauses to fix its dragline, then springs.
- We found no full list of what the house jumping spider eats. Booklice are the only prey named in our sources.
Sources [2, 4, 7, 9]

Tap a pin on the model or a part below.

Sharpest eyes of any land invertebrate
- The two huge front eyes are the main (principal) eyes. They see finer detail than any other eyes known in land invertebrates.
- Each one works like a little telescope: a lens at the front, a second lens further back and a narrow strip of retina at the end.
- The lenses can’t move, but the retinas behind them can. That is how the spider looks around without turning its head.
Sources [1, 2, 3]
≈360° view from all 8 eyes
- Jumping spiders have eight eyes in four pairs. Together they see almost all the way around the spider.
- The smaller side eyes see a wide area and are very good at spotting movement. When they notice something, the spider turns to face it.
- Then the big front eyes take a close look. They can only follow a moving object smoothly when the side eyes guide them.
Sources [1, 3, 4]
Pair 3 main push-off legs
- High-speed films show that the house jumping spider jumps mainly with its long third legs. Its short fourth legs let go of the ground earlier.
- A close relative, Sitticus pubescens, does it the other way round and pushes mostly with its fourth legs.
- The third legs point forwards, so they pull the body along as they straighten, while back-pointing fourth legs push.
Sources [5]
- Each foot ends in a tuft of tiny hairs called a claw tuft. These hairs grip smooth surfaces like glass and leaves.
- When scientists removed the claw tufts, the spiders slipped as they tried to jump. The grip is what makes a clean take-off possible.
- Different parts of the tuft are used for pulling and for pushing.
Sources [5]
- Jumping spiders often have larger front legs. They help to hold prey after the pounce.
- In many species the front legs are also used for signalling, waved in the air during courtship.
- Before a jump, legs like these are straightened by body-fluid pressure, not only by muscles.
Sources [2, 6]
- The palps are the two short feelers beside the jaws. They look a bit like tiny boxing gloves on an adult male.
- In jumping spiders, males often have extra hair tufts or colours and show them off to females.
- Palps and front legs are flicked and waved in courtship displays that are among the most elaborate of any spiders.
Sources [2, 7, 8]
- The jaws (chelicerae) end in small fangs that hold and bite prey after a pounce.
- The house jumping spider has been seen feeding on booklice, tiny insects that live indoors.
- Its fangs are tiny. Spider bites are rare, and medical experts don’t count this spider among the few dangerous ones in its home region.
Sources [9, 10]
3–5 mm body length
- Its scientific name, lanigera, means wool-bearing. The body is covered in fine hairs.
- Males are 3–4 mm long and females up to 5 mm, smaller than a grain of rice.
- The genus name Pseudeuophrys roughly means false beautiful-eyebrows. It was split off from the genus Euophrys.
Sources [9]
- Silk comes out of the spinnerets at the tip of the abdomen. Jumping spiders don’t use it to build webs for catching prey.
- Before a jump, the spider fixes a silk dragline to the surface. It steadies the jump and lets the spider climb back if it misses.
- Silk is also used to build small tents where jumping spiders shelter from bad weather and sleep at night.
Sources [2, 11]

Real house jumping spiders

Photos from Wikimedia Commons. Some of them can repaint the 3D model.

House jumping spider, femaleUp to 5 mm long. Dark brownish with fine woolly hairs and big, shiny front eyes.Found on walls and inside houses all yearA female found in an upstairs shower in Ipswich, England. Houses are where this spider is most often found.. Photo: Martin Cooper, CC BY 2.0
House jumping spider, maleSmaller, 3–4 mm long, with large palps at the front. In jumping spiders, males are often more strongly marked or tufted than females.Shows off to females with leg and palp signalsAn adult male. Males are 3–4 mm long, a little smaller than females.. Photo: Backslash, CC BY-SA 3.0
This one was about 3.5 mm long. Its fine hairs explain the name lanigera, wool-bearing.Photo: Thomas Wydra, CC BY-SA 3.0 DE
In Buckinghamshire, England. Britain has about 1,200 shared records of this spider.Photo: kitenet, CC BY 2.0
In a back garden in Stevenage, England.Photo: Ben Sale, CC BY 2.0
The two big front eyes see sharper detail than any other land invertebrate’s eyes.Photo: Alexis Lours, CC BY 4.0
A macro view of a house jumping spider.Photo: Darxmurf, CC BY-SA 4.0
Zebra jumping spiderSalticus scenicus: a bigger relative with black and white stripes. Females are 5–9 mm and males 5–6 mm long.Hunts on sunny walls, fences and rock facesThe zebra jumping spider, a bigger striped relative that also hunts on walls.. Photo: Zavadluk, CC BY-SA 4.0
Zebra jumping spiderSalticus scenicus: a bigger relative with black and white stripes. Females are 5–9 mm and males 5–6 mm long.Hunts on sunny walls, fences and rock facesA zebra jumping spider close up. Females reach 5–9 mm.. Photo: Harald Hoyer, CC BY-SA 2.0

House jumping spider by the numbers

Measured by scientists, for this species or its jumping spider relatives.

Female body: ≤5 mm; smaller than a grain of rice⁠[9]; Female (max)5 mmMale (max)4 mm
Male body: 3–4 mm; males are the smaller sex⁠[9]
Eyes: 8; in four pairs; one huge front pair⁠[2, 3]
Field of view: ≈360°; from all eight eyes together⁠[3]
Retina layers: 4; stacked light-cell layers in each big front eye⁠[14, 2]
Jumping legs: Pair 3; the long third legs give most of the push⁠[5]
Adults seen: 12 months; indoors, even in deep winter⁠[9]
Hearing distance: ≈3 m; a jumping spider (Phidippus audax) reacted to a sound this far away⁠[21]
Jumping spider species: 6,000+; the largest spider family⁠[8, 2]
GBIF records: 8,146; 1,197 of them from Britain⁠[22]

House jumping spider: myth or fact?

Some popular jumping spider facts are true, some are stretched and some are wrong.

0 of 8 answered

“House jumping spiders are insects.”
“A jumping spider can jump 50 times its own body length.”
“Their legs work like springs.”
“Jumping spiders see colours just like people do.”
“All eight of its eyes look forwards.”
“A jumping spider can’t move its eyes.”
“Jumping spiders tie on a safety line before they jump.”
“Spiders can’t hear sounds in the air.”

House jumping spider family records

The house jumping spider belongs to the jumping spider family, which holds some remarkable spider records.

Sharpest eyes
No. 1
Jumping spiders’ big front eyes
the best detail vision known in any land invertebrate, beating all insects⁠[1, 3]
Best daytime eyesight
Best of all spiders
Jumping spider family
the record list of spider achievements gives this title to the whole family⁠[8]
Biggest spider family
6,000+ species
Jumping spiders (Salticidae)
about 13% of all spider species⁠[8, 2]
Highest-living spider
≈5,900 m
Euophrys omnisuperstes, a relative
a male from Mount Makalu; young spiders found at about 6,700 m on Everest may be the same species⁠[8]
Longest jump measured
38 body lengths
Colonus puerperus
reported for one spider; most species jump much shorter⁠[2]
Fastest take-off
Fastest acceleration
Splendid peacock spider
of all jumping spiders measured so far, filmed at 5,000 frames per second⁠[19]
Most elaborate courtship
Top of the list
Jumping spider family
males dance, wave legs and palps, and some drum and buzz as well⁠[8, 17]

A house jumping spider’s life

Little has been studied about this species’ life, and its lifespan is not known. This is what we know from it and its close relatives.

Start
Eggs in a silk tent
Jumping spiders keep their egg sacs inside small silk shelters.⁠[7]
Hatching
See-through spiderling
For a short time a newly hatched jumping spider’s skin is clear, so the moving retinas inside its eyes can be seen.⁠[15]
Growing up
Life on the walls
The young spider hunts on and inside buildings. It copes with dry, modern concrete houses better than the zebra spider does.⁠[9]
Any month
Adult
Adults can be found all year indoors, even in deep winter. Males reach 3–4 mm and females up to 5 mm.⁠[9]
Courtship
The dance
Male jumping spiders court with leg and palp displays. The house jumping spider’s own dance has not been described in detail.⁠[8, 7]
Every night
Rest in a tent
Jumping spiders rest in silk tents at night. One species shows bursts of retinal movement that may be a kind of dreaming sleep.⁠[2, 15]

House jumping spider vs zebra spider vs crab spider

Two jumping spiders that share European walls, and a flower-sitting crab spider.

House jumping spider vs zebra jumping spider vs goldenrod crab spider
	House jumping spider	Zebra jumping spider	Goldenrod crab spider
Scientific name⁠[9, 16, 25]	Pseudeuophrys lanigera	Salticus scenicus	Misumena vatia
Body length⁠[9, 16, 25]	Males 3–4 mm, females up to 5 mm	Females 5–9 mm, males 5–6 mm	Males 3–5 mm, females 7–11.5 mm
Colours⁠[9, 16, 25]	Dark and woolly-haired	Black and white stripes	White, pale green or yellow
Where to look⁠[9, 16, 25]	On and inside buildings	Sunny walls, fences and rock faces	On flowers
How it hunts⁠[7, 16, 25]	Stalks, then jumps	Stalks, then jumps	Waits on a flower and grabs visitors
Web to catch prey⁠[2, 25]	No	No	No
Range⁠[9, 26, 16, 25]	Western and southern Europe to the Caucasus; spreading, now in North America	Europe, North America and northern Asia	Europe, Asia and North America

Sizes from different sources; individual spiders vary.

Is the house jumping spider endangered?

No sign of it. The house jumping spider has never been assessed for the IUCN Red List, and it seems to be spreading.

IUCN Red List

Not Evaluated (NE)

Trend unknown

It has been recorded in at least 25 countries, mostly in Europe. It was first found in Germany in the 1950s, in Poland in 1999 and in North America by 2017.⁠[27, 22, 9, 28, 26]

Not evaluated (Wikidata and GBIF, checked 2026)

Threats

No known threats
We found no study of threats to this species. Because it lives on and in buildings, its future is tied to ours.⁠[9]

What’s helping

Record sightings
More than 8,000 records of it are shared online. Photos from homes and gardens help scientists track how far it spreads.⁠[22, 29]
Watch, don’t catch
It eats tiny indoor insects such as booklice. Leaving it on the wall lets it keep hunting.⁠[9]
No need to fear it
Spider bites are rare, and this spider is not one of the few medically important species in its home region.⁠[10]

Relatives

Zebra jumping spider (Salticus scenicus)Not Evaluated
Not assessed. Widespread across Europe, North America and northern Asia.⁠[30, 16]

House jumping spider quiz

12 questions. Every answer is somewhere on this page.

Question 1 of 12Score 0

How long is an adult female house jumping spider?

House Jumping Spider field notes

Diet, food web, safety and badges from the Snappit field guide.

Diet & Feeding

Tiny hunters, they eat small insects found indoors, such as booklice. They stalk their prey and then pounce.

Primary Foods

Flies
Mosquitoes
Gnats
Booklice
Moths
Foraging Method: Pursuit

Ecological connections

Common House FlyHunts
Actively stalks and pounces on flies found indoors.
Common House MosquitoHunts
Preys on adult mosquitoes, helping control their numbers.
Barn Funnel WeaverEaten by
Larger house spiders sometimes ambush and eat them.

Safety

Danger 1/5 · Very low

House Jumping Spiders are not dangerous and can be safely observed, but it's best not to touch them.

Traits

Collections

Insects

Classification

Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Family: Salticidae
Genus: Pseudeuophrys

Sources for these house jumping spider facts

31 studies and references · checked Oct 16, 2026

Frequently Asked Questions

How to identify House Jumping Spider?

Compare body proportions, leg shape, abdomen markings and the web, if there is one. Eye arrangement can be decisive but rarely shows up in a casual phone photo. A web is a supporting clue, not proof of who built it. Spider Identifier: upload a photo and compare the visible details.

How big is House Jumping Spider?

3-5 mm

How long does House Jumping Spider live?

365-730 days

What does House Jumping Spider eat?

Tiny hunters, they eat small insects found indoors, such as booklice. They stalk their prey and then pounce.

Where is House Jumping Spider usually found?

You can find them in homes, gardens, and other places where they can hunt for insects.

How does House Jumping Spider hunt?

Pursuit

How many legs does House Jumping Spider have?

Is the house jumping spider dangerous?

No. Spider bites are rare, and in the Mediterranean region, where this spider comes from, only two spider species are considered medically important. The house jumping spider is not one of them. Still, watch it rather than pick it up, and tell an adult if anything bites you. Washing with soap and water and a cold compress help with most bites.

Why do I have jumping spiders in my house?

The house jumping spider lives mostly on and inside buildings. It copes with dry, modern houses well, and adults can be found indoors all year, even in winter.

How far can a jumping spider jump?

It depends on the species. Some jump 2–3 body lengths, and one Colonus puerperus spider was measured at 38 body lengths. The popular claim of 50 body lengths is not backed by any study we found.

How many eyes does a house jumping spider have?

Eight, in four pairs. The two huge front eyes see fine detail, and the smaller side eyes spot movement. Together they see almost all the way around.

Can jumping spiders see colour?

Some can. A few colourful species have three-colour vision, while at least one can’t tell red from black. Colour vision hasn’t been tested in the house jumping spider.

What do house jumping spiders eat?

Small insects. It has been seen eating booklice, which live indoors. It stalks its prey and then pounces.

Do jumping spiders sleep?

They rest at night in silk tents. One study found regular bursts of eye movements with leg twitches at night, which may be a sleep state like our dreaming sleep. It is not proven yet.

Is the house jumping spider the same as the zebra spider?

No. Both are jumping spiders found on walls, but the zebra spider (Salticus scenicus) is bigger, 5–9 mm, and has black and white stripes. The house jumping spider is smaller, darker and woolly.