The belief that only female spiders construct webs is a common misunderstanding. Both male and female spiders possess the biological machinery to produce silk throughout their lives. The confusion stems from the fact that the large, intricate, and highly visible structures people typically associate with spiders—like the classic orb web—are almost exclusively built by the female. Their differing roles in the life cycle lead to a significant difference in how the two sexes utilize their silk.
The Universal Ability to Produce Silk
Silk production is a trait shared by almost all spiders, regardless of sex, making it a fundamental aspect of their biology. The ability to spin is rooted in specialized organs called silk glands, located in the abdomen, which extrude liquid protein through tiny spigots on the spinnerets. A single spider can produce up to seven different types of silk, each with unique mechanical properties for a specific function.
Both males and females rely on robust dragline silk, a protein fiber that acts as a safety tether for mobility and survival. This silk is continuously laid down as the spider moves, ensuring a quick escape route should they fall or encounter a threat. They also produce silk for basic needs like lining temporary shelters or creating anchor points. This foundational silk usage is universal, but the complexity and volume of production distinguish the sexes.
Gendered Roles in Web Construction
Female Silk Use
The difference in silk use is driven by the biological pressures of reproduction and growth. Female spiders must grow substantially larger than males to produce egg masses, requiring a constant, high-volume energy source. The intricate, expansive structures seen in nature, such as orb webs or sheet webs, are capture webs built by females for hunting. This structure is a passive trap, allowing the spider to remain stationary while catching food to sustain her body and prepare for laying eggs. Female spiders also produce specialized silk for constructing tough, protective egg sacs, and their webs often incorporate pheromones to attract distant males.
Male Silk Use
Male spiders dedicate their silk usage almost entirely to mobility, survival, and mating rituals rather than large-scale hunting. As they mature, many males leave their hunting webs behind to wander in search of a mate, using their draglines for safety or for dispersal through the air, a process known as ballooning. The most specialized structure created by the mature male is the sperm web, a small, temporary pad of silk. The male deposits sperm onto this sheet and then draws it into his pedipalps, the copulatory organs near his mouth. Silk also plays a direct role in courtship, as males often deposit threads on the female’s existing web to transmit vibratory signals or confirm her receptivity, sometimes even restraining the female during mating.