Can Male Spiders Make Webs and Why They Are Different

Male spiders can produce silk and, in many species, do build webs during their juvenile stages. But something changes when they reach sexual maturity: across a wide range of web-building families, adult males scale back silk production, shrink or lose key silk-producing structures, and often stop building prey-catching webs altogether. The differences between male and female silk use run deep, from the physical spigots on their spinnerets down to the genes that code for silk proteins, and they reflect a life that has been reorganized around a single goal: finding a mate.

What Male Spiders Still Spin

Even in species where adult males never construct a prey web, they still use silk constantly. Every spider, male or female, trails a dragline behind it as it moves. This strand of silk functions like a climbing rope and a safety line, anchoring to surfaces at intervals and letting the spider catch itself during a fall or retrace its steps. Males wandering across terrain in search of females rely on draglines for navigation and survival, and the major ampullate glands that produce dragline silk remain functional in males throughout their lives.

Males also spin small, purpose-built sheets of silk called sperm webs. Before mating, a male deposits sperm onto this tiny web and then draws it up into his pedipalps, the pair of leg-like appendages near his mouth that serve as sperm-transfer organs. The sperm web is simple compared to an orb web or a funnel web, but it requires functional silk glands and precise placement. It is one of the most widespread silk behaviors in male spiders, found in families as distantly related as orb weavers and jumping spiders.

Young males in many species also use silk for ballooning, releasing a strand into the wind to be carried to a new location. This dispersal behavior is shared with females and juveniles, and it highlights that the silk machinery in males is not absent. It is repurposed. What changes at maturity is not whether a male can produce silk, but how much of the silk-making apparatus he retains and what he does with it.

How Silk Hardware Changes at Maturity

Spider silk comes out of spinnerets, the finger-like structures at the rear of the abdomen. Each spinneret carries multiple spigots, and each spigot connects to a specific type of silk gland. Females typically have a full complement of gland types that produce everything from sticky capture threads to tough structural fibers to the specialized silk used to wrap egg sacs. Males often start life with the same set of spigots, but as they molt toward adulthood, some of those spigots deteriorate.

A study of male pirate spiders in the genus Australomimetus documented this process in detail. Cylindrical gland spigots, which females use to produce egg-sac silk, were present in juvenile males. But by adulthood, roughly 75% of these spigots on adult males had degraded into what researchers described as “nubbins,” essentially a base with no shaft, incapable of channeling silk. Only about a quarter of the spigots retained a functional shaft, and even those kept a juvenile shape rather than developing the stout, mature form seen in females.¹ The males were not born without the equipment. They lost it over the course of development.

This pattern is not limited to pirate spiders. Across web-building families, researchers have found that adult males tend to retain the glands responsible for dragline silk and attachment discs while losing or reducing the glands associated with prey capture and egg production. The result is a streamlined silk toolkit: enough to navigate, build a sperm web, and sometimes lay down courtship signals, but not enough to construct and maintain a full-scale prey trap.

Gene Expression Tells a Similar Story

The physical loss of spigots reflects deeper changes at the molecular level. When researchers profiled the genes active in silk and venom glands of the wolf spider Pardosa astrigera, they found marked differences between males and females. Hundreds of genes were differentially expressed between the sexes, and the patterns sorted into distinct groups: some modules of co-expressed genes were tied to development, while one module was specifically male-biased.² Spidroin genes, which encode the core proteins in spider silk, were distributed across multiple modules, suggesting that silk production is not simply switched off in males but regulated in a different pattern. Males still express silk genes. They just do not express the same ones, in the same amounts, at the same life stages as females.

This kind of sex-specific regulation fits with what we see in the spigots: the male body is not failing to build silk hardware because of some defect. It is actively dialing down certain silk programs during development, presumably because the energetic cost of maintaining a full silk arsenal no longer pays off once mating becomes the priority.

Why Mobility Beats Web-Building

The central explanation for why so many adult male spiders abandon web construction comes down to two competing demands: feeding and mating. A web is a passive trap. It requires time and energy to build, and it ties the builder to one location. For a female, who needs a steady flow of nutrients to produce eggs, that investment makes sense. For a male, who needs to travel potentially long distances to find a receptive female, being anchored to a web is a liability.

This trade-off is especially stark in species with extreme size differences between the sexes. In golden silk orbweavers (Nephila), females build enormous orb webs and remain in them for most of their adult lives, while males stop web-building entirely at their final molt and switch to roaming.³ The males are a fraction of the female’s size, sometimes less than a tenth of her body mass. That size difference is not random. Research into spider energetics suggests that natural selection favors smaller males in species where males must travel to find mates, because a smaller body means lower energy costs per unit of distance traveled. Long legs relative to body size compound the advantage, increasing speed without proportionally increasing weight.⁴

The logic is straightforward: a male who invests in building and maintaining a web is a male who is not searching for females. In species where population density is low and females are widely scattered, the energetic savings of being small and web-free give roaming males a reproductive edge. The silk glands that would have supported a full web become unnecessary weight, and evolution has gradually pared them down.

How Males Eat Without a Web

If an adult male is not catching prey in a web, what does he eat? The answer varies, and in some cases, the honest answer is “not much.” Many adult male spiders have a limited adult lifespan measured in weeks, and they may survive largely on reserves built up during their final juvenile instar, when they were still web-building and feeding actively. Their bodies are smaller, their metabolic demands lower, and their reproductive window short enough that starvation is a race they sometimes lose to mating.

Some males adopt alternative feeding strategies. Male crab spiders of the species Misumena formosipes provide a striking example. Females of this species can be 20 to 50 times heavier than males, and adult males seldom feed on prey. Instead, researchers documented something previously unproven for any spider: the males drink nectar from flowers.⁵ Nectar provides a quick sugar source that does not require the time and risk of subduing prey, and it fits neatly into a lifestyle organized around mate-searching. The males spend their time guarding potential mates on flowers, and the flowers themselves become fuel stations.

In web-building species, some males practice kleptoparasitism, stealing prey from the webs of females they have located. A male golden orbweaver sitting on the periphery of a female’s massive web can snag small insects caught in the silk without building anything himself. This behavior blurs the line between “does not use a web” and “does not build a web.” The male is still benefiting from web-based prey capture, just not from his own silk.

Males on Female Webs

When an adult male locates a female’s web, he does not simply walk onto it. The web is a sensory organ for its builder, and an unannounced arrival is likely to be treated as prey. Males use silk and vibration in highly specific ways to signal their identity and intentions. In orb-weaving species, a male will typically pluck or strum specific threads on the female’s web, producing vibration patterns distinct from the struggling of trapped insects. Some males add their own silk to the web during courtship, laying down signal threads or creating modified zones that transmit their vibrations more clearly.

This courtship signaling relies on the male’s remaining silk glands. Dragline silk and attachment silk are critical here: the male needs to anchor himself, control his position, and sometimes construct a mating thread, a single line of silk on which he positions himself during sperm transfer. In some species, the male partially dismantles or restructures a portion of the female’s web before mating, which may reduce the female’s ability to detect his movements or may function as a form of mate guarding by making the web less attractive to rival males. These behaviors make clear that silk remains a tool of central importance to the male. He just wields it in a fundamentally different context than prey capture.

Social Spiders Break the Mold

Not all spider species follow the “females build, males roam” template. In social spiders, which live in cooperative colonies sharing a single communal web, the division of labor looks different. Males in these species do not leave the web to search for mates, because potential mates are already in the colony. That removes the main evolutionary pressure driving web abandonment.

In the group-foraging spider Stegodyphus dumicola, males were found to be more cooperative than females, not less. Researchers measured how frequently individuals produced food for other group members and found that males had significantly higher cooperative tendencies across all groups studied.⁶ Males contributed to web maintenance and prey capture alongside females, and their cooperative behavior benefited both their own fitness and the productivity of the kin group. In this social context, the male spider’s relationship with the web is cooperative rather than exploitative, and his silk-producing abilities remain relevant throughout adult life.

Social spider species are a minority. Most of the roughly 50,000 known spider species are solitary, and among solitary web-builders, the pattern of male silk reduction holds broadly. But the social species demonstrate that the male body plan retains the capacity for web construction when the ecological conditions favor it. The reduction in male silk production is not a hard-wired, irreversible loss across the evolutionary tree. It is a flexible response to the mating system.

Wandering Spiders and the Species That Never Built Webs

The framing of “males stop building webs” applies most cleanly to species in which females are dedicated web-builders. But many spider families, including wolf spiders, jumping spiders, and huntsman spiders, are active hunters that never build prey-catching webs regardless of sex. In these families, the difference between male and female silk use is less dramatic, because neither sex relies on a web for feeding.

Males in these hunting families still produce dragline silk, still build sperm webs, and in some cases still construct retreat shelters from silk. The sex-based differences tend to show up in more subtle ways: females may produce thicker draglines, spin more elaborate egg sacs, or use silk-lined burrows more extensively. Male wolf spiders, for example, use silk primarily for sperm induction and for vibratory courtship signals performed on leaf litter or soil surfaces. Their silk production is modest, but it was never as elaborate as an orb weaver’s to begin with.

The practical upshot is that the question “can male spiders make webs?” has different answers depending on which spider you are asking about. In an orb weaver, the answer is “yes as a juvenile, usually not as an adult.” In a jumping spider, the answer is “webs are not really the point for either sex, but both use silk.” In a social spider, the answer is “yes, and he may contribute more than the females.” The common thread is that silk production in males is shaped by whether the silk helps him reproduce. When it does, it persists. When it does not, it fades.

The Short Adult Life of Male Spiders

One factor that rarely makes it into popular discussions of spider silk is just how compressed the adult male’s life tends to be. In many species, the male’s final molt marks the beginning of a rapid countdown. His mouthparts may become less functional for feeding, his energy reserves are finite, and he has days to weeks to find a mate before he dies. In some widow and orbweaver species, the male does not survive the mating encounter itself.

Under these constraints, the investment calculus for silk production changes dramatically. Building a web might keep you alive a few extra days, but those extra days spent stationary are days not spent searching. For a male crab spider subsisting on flower nectar while guarding a female, or a male orbweaver picking scraps from the edge of his mate’s web, the resources that would have gone into web construction are better spent on locomotion and courtship.⁵ The energetics research supporting small male body size as an adaptation for reduced transport costs reinforces this interpretation: everything about the adult male spider’s body, including his downsized silk glands, is optimized for a brief, mobile reproductive life.⁴

Silk remains central to spider biology regardless of sex. Both males and females depend on it from the moment they hatch. But the story of male silk is a story of selective retention: keeping what serves mating and movement, shedding what served a sedentary feeding lifestyle the adult male no longer leads. The glands shrink, the spigots degrade, the gene expression profiles shift, and the male that emerges from his final molt is equipped not for building, but for traveling.