Spiders produce intricate silken structures that serve as tools for hunting prey, protecting offspring, and travel. The creation and maintenance of these networks are central to a spider’s existence, prompting curiosity about their ultimate fate.
The Surprising Truth: Yes, They Do!
Many spider species consume their own webs, a behavior that might seem counterintuitive. This act is a common practice observed across various spider families, including orb-weavers. Rather than abandoning damaged or old webs, these arachnids actively reclaim the silk material.
Why Spiders Consume Their Silk
Spiders invest metabolic energy and protein resources into producing silk for their webs. Consuming an old or damaged web allows them to reclaim a significant portion of these valuable components. This recycling conserves resources needed for building new structures, particularly where food is scarce.
Beyond resource conservation, web ingestion also aids water recovery, especially in drier climates. Webs, particularly large orb webs, collect dew and condensation. By consuming the silk, spiders absorb this trapped moisture, providing hydration that supplements their direct water intake. This helps them maintain water balance in challenging conditions.
Silk is primarily composed of proteins, specifically fibroin. When spiders ingest webs, they break down these proteins into amino acids through digestion. These recovered amino acids are re-utilized for various metabolic functions, including new silk production, egg development, or general body maintenance. Additionally, eating old webs helps spiders maintain a clean environment, removing tattered or non-functional structures that could attract predators or parasites.
The Process of Web Ingestion
When consuming its web, a spider typically begins by gathering the silk threads. Many species use their legs and pedipalps to pull and collect the strands, often rolling them into a compact ball or pellet. This ensures the entire structure is efficiently collected before ingestion.
Once the silk is gathered into a manageable ball, the spider begins oral processing. It often applies digestive enzymes from its mouthparts onto the silk pellet. These enzymes initiate the external breakdown of silk proteins, making subsequent internal digestion more efficient.
The partially broken-down silk is then ingested. Spiders possess specialized digestive systems capable of further processing these proteins. Through enzymatic action within their gut, complex proteins are broken down into simpler amino acids and peptides, which are absorbed into the bloodstream. While orb-weavers are well-known for this behavior, other spider types, such as sheet web weavers, may also exhibit similar recycling habits.