Quick answer: Nursery web spiders are long-legged hunting spiders in the family Pisauridae. They do not build webs to catch food. Instead, the female carries her round egg sac in her jaws and, just before the spiderlings hatch, spins a silk “nursery” tent in vegetation and guards it.
In Europe the name usually means Pisaura mirabilis. In North America it usually means Pisaurina mira, the American nursery web spider. Neither is considered dangerous to people.
Which spider is the “nursery web spider”?
The common name depends on where you live, so it helps to start with geography.
- Europe, North Africa and parts of Asia: Pisaura mirabilis. The World Spider Catalog lists it from Morocco and Europe east through Turkey, the Middle East, the Caucasus and Russia to Central Asia and China. It is common and widespread in much of Britain.
- Eastern North America: Pisaurina mira. BugGuide gives its range as New England and southern Ontario west to Minnesota and south to Texas and Florida. Other Pisaurina species also occur in the region.
Both belong to Pisauridae, a family of roughly 45 genera and about 235 species according to the World Spider Catalog (checked October 2026).
A recent change to note: Fishing spiders and raft spiders (genus Dolomedes) were long treated as members of Pisauridae, and many older books and websites still say so. Following a 2025 phylogenetic study, the World Spider Catalog now places Dolomedes and several related genera in a separate family, Dolomedidae. They are close relatives with similar habits, but they are no longer counted as nursery web spiders in the strict family sense. For the semi-aquatic group, see our guide to fishing spider size, diet and habitat.
How to identify a nursery web spider
Color is a poor guide here. Individuals range from pale tan to rusty, grey or dark brown, and the pattern varies from one spider to the next. Shape, posture, eyes and behavior are more reliable. For a general method that works on other spiders too, see the Spiderpedia spider identification guide.
Clues for the European nursery web spider (Pisaura mirabilis)
- Resting posture: It often sits on a leaf or stem with the first two pairs of legs held close together and stretched forward. This is one of its most recognizable habits.
- Front body (carapace): A thin pale line runs down the middle, edged by broader dark bands.
- Abdomen: Long and tapering toward the rear, often with pale bands along the sides.
- Position: It usually hunts and basks on taller plants rather than on bare ground.
- Female with a large round egg sac in her jaws (early to mid summer): a strong clue, because few similar-sized spiders carry the sac this way.
Clues for the American nursery web spider (Pisaurina mira)
- Slender build and long legs, often held out in pairs along a stem or leaf edge.
- Usually tan to brown, often with lengthwise stripes or pale spots along the sides. The pattern varies with the individual and its age.
- Found on plants and shrubs in fields, woodland edges, roadsides, parks and gardens rather than at ground level.
Size
Sizes below are body length, not leg span. With legs spread, the spider looks considerably larger.
| Species | Female body length | Male body length |
|---|---|---|
| Pisaura mirabilis | about 12–15 mm | about 10–13 mm |
| Pisaurina species (Missouri guide) | about ½–¾ inch (13–19 mm); males smaller | |
Nursery web spider vs. wolf spider
Nursery web spiders are most often mistaken for wolf spiders (family Lycosidae). Both are hunters that do not use a capture web, but a few features separate them.
| Feature | Nursery web spiders (Pisauridae) | Wolf spiders (Lycosidae) |
|---|---|---|
| Eyes | Eight eyes in two rows, all of fairly similar size | Eight eyes in three rows, with two eyes clearly larger than the rest |
| Egg sac | Held in the jaws and palps, under the front of the body | Attached to the spinnerets and dragged behind |
| Young | Kept in a silk nursery tent that the mother guards | Climb onto the mother’s back and ride there for a time |
| Where you see them | Usually up in vegetation | Usually on the ground |
| Body shape | Longer, more tapering abdomen; long slender legs | Often stockier, with a broader body |
The eye pattern is the most reliable of these clues, but you need a clear, close photo from the front to see it. The egg-sac and nursery behavior only help with adult females in season.
How nursery web spiders hunt
Nursery web spiders use silk for safety lines, egg sacs and nurseries, not for trapping prey. They catch insects and other small invertebrates by sitting still on vegetation until something comes close, or by moving toward prey and seizing it. Their good motion-sensitive eyesight and long legs make both approaches work.
Because they rely on movement rather than a web, you are more likely to notice one basking on a nettle or bramble leaf on a sunny day than sitting in silk. Hunting habits like this are covered in more depth in our spider behavior section.
The nursery web: from egg sac to spiderlings
The family’s common name comes from the way females care for their young. The details below follow the British Arachnological Society’s account of Pisaura mirabilis in Britain; timing will differ in other climates.
- Egg sac: A little over a week after mating, the female makes a round, cream-colored egg sac about 7–8 mm across. It often holds around 150 eggs; published figures range from roughly 100 to 300.
- Carrying it: She holds the sac in her jaws for about three weeks. In this period she moves it above or below a leaf, which helps keep it at a suitable temperature.
- Building the nursery: When the young are about to emerge, she spins a dense, roughly cone-shaped tent across the tops of grasses, nettles, rushes or similar plants and places the sac inside.
- Guarding: She stays with the nursery, first inside it and then patrolling outside once the spiderlings emerge.
- Dispersal: The young cluster tightly by day and spread through the web at night. After about four to seven days they leave and live on their own.
American nursery web spiders follow a similar pattern. Missouri’s conservation department notes that the nursery is often well off the ground, sometimes in a leaf folded and tied with silk, and that the mother stays until the young disperse.
Not every member of Pisauridae builds a nursery web. The habit is well known in Pisaura and Pisaurina, but specialists point out that it is found in only some pisaurid species and also appears in a few other spider families.
Courtship and the “wedding gift”
Pisaura mirabilis is well known among researchers for its nuptial gift. Before courting, a male catches an insect, wraps it in silk and carries it in his jaws. If the female accepts the gift, she feeds on it while they mate.
Studies of this species have found several interesting details:
- Gifts improve mating success. Males without a gift are far less likely to mate, and larger gifts are linked to longer mating.
- Some gifts are fakes. Males sometimes wrap inedible material, such as plant matter or the empty remains of an already-eaten insect. In laboratory trials, males with worthless gifts still mated at a similar rate, but females ended mating sooner and less sperm was transferred.
- Males may play dead. When a female tries to take the gift and break off mating, a male may go motionless while keeping hold of it. Researchers found that this behavior mainly helps males mate for longer.
- Sexual cannibalism is uncommon. In one study, females killed males in only about 2.5% of more than 300 trials. A later experiment found that males courting without a gift were attacked more often, which suggests the gift also offers some protection.
Where and when you will see them
Habitat
Pisaura mirabilis lives in rough grassland, heathland, roadside verges, open woodland and woodland edges, and often turns up in gardens with long grass or nettles. The Spiders of Europe database describes it as very common in open habitats such as damp meadows and scrub. In North America, Pisaurina species use similar places: tall grass, field and woodland edges, fencerows, roadsides, parks and garden shrubs. For more on how habitat narrows down identification, see spider habitats.
Season
In Britain, males mature in May and June and females a few weeks later. Most males are dead by August, while females live longer, and in southern England some produce a second egg sac in September or October. Spiderlings reach about half their adult size by winter and spend the cold months near the base of grasses, maturing the following year.
BugGuide notes that adult American nursery web spiders are active from spring to early autumn.
Distribution in Britain
In Britain, the species is common and widespread from northern England to the south coast. It becomes patchier further north and is scarce on high ground such as Dartmoor, Exmoor, the Pennines and the Welsh mountains.
Are nursery web spiders dangerous?
No. They are not considered dangerous to people. Missouri’s conservation department describes Pisaurina nursery web spiders as harmless to humans, and NC State’s Plant Disease and Insect Clinic notes that they are neither aggressive nor dangerous, even though they are sometimes mistaken for brown recluses. The European species is a similar mid-sized hunter that spends most of its time up in vegetation, away from people.
Like nearly all spiders, they are venomous in the sense that they use venom to subdue prey. That is not the same as being harmful to humans. A large spider of any kind may bite if it is grabbed or pressed against the skin, so the simplest approach is to leave it alone or guide it outdoors on a piece of card. If anyone develops a reaction that is severe, spreading or getting worse, they should get medical advice. Symptoms alone cannot show which spider, or whether any spider, was involved.
Nursery web spiders also eat many garden insects. For the wider picture, read why spiders are important, or browse other groups in spider types.
References
- World Spider Catalog. Family Pisauridae Simon, 1890. Natural History Museum Bern. wsc.nmbe.ch/family-detail/79 (accessed October 2026).
- World Spider Catalog. Pisaura mirabilis (Clerck, 1757). wsc.nmbe.ch/species/27464 (accessed October 2026).
- World Spider Catalog, archive version 26. Family Dolomedidae Simon, 1876. wsc.nmbe.ch.
- Nentwig W., Blick T., Bosmans R., Gloor D., Hänggi A. & Kropf C. Spiders of Europe: Pisaura mirabilis. araneae.nmbe.ch/data/812.
- British Arachnological Society. Nurseryweb Spider (Pisaura mirabilis) species sheet. britishspiders.org.uk.
- Missouri Department of Conservation. Nursery Web Spiders (field guide). mdc.mo.gov.
- BugGuide. Pisaurina mira – Nursery Web Spider. Iowa State University. bugguide.net/node/view/2919.
- NC State Extension, Plant Disease and Insect Clinic (2022). Late Spring Spiders: Common but Not Dangerous. pdic.ces.ncsu.edu.
- Vink C.J. & Dupérré N. (2010). Pisauridae (Arachnida: Araneae). Fauna of New Zealand 64. Landcare Research.
- Albo M.J., Winther G., Tuni C., Toft S. & Bilde T. (2011). Worthless donations: male deception and female counter play in a nursery web spider. BMC Evolutionary Biology 11: 329. PMC3228764.
- Hansen L.S., Fernández González S., Toft S. & Bilde T. (2008). Thanatosis as an adaptive male mating strategy in the nuptial gift–giving spider Pisaura mirabilis. Behavioral Ecology 19: 546–551.
- Toft S. & Albo M.J. (2016). The shield effect: nuptial gifts protect males against pre-copulatory sexual cannibalism. Biology Letters 12: 20151082. PMC4892239.
