Baby spiders, known as spiderlings, are often capable of surviving independently immediately after hatching. While some spider mothers provide extended care, for most of the thousands of spider species, independence is the standard from birth. Female spiders protect their eggs within an egg sac, and once spiderlings emerge, they are typically equipped to begin their solitary lives.
The Default: Independent Spiderlings
For the vast majority of spider species, maternal care concludes at or shortly after the egg-laying stage. A female spider meticulously constructs a silk egg sac to protect her eggs. This sac can contain anywhere from a few dozen to several thousand eggs, varying significantly by species. She might attach this sac to her web, hide it, or abandon it, depending on her species’ strategy.
Once spiderlings hatch, they emerge as miniature versions of adult spiders. They often undergo their first molt while still inside the egg sac, shedding their exoskeleton before breaking free. After emerging, these young arachnids typically disperse quickly, ready to navigate the world independently.
How Spiderlings Survive Solo
Spiderlings possess innate adaptations and behaviors enabling their survival without maternal intervention. Upon hatching, many spiderlings still have remnants of a yolk sac, providing them with initial nourishment. In some instances, they may even consume unhatched eggs or weaker siblings for their first meal, a form of larval cannibalism.
Dispersal is a primary survival mechanism, allowing spiderlings to spread out and avoid competition with siblings. Many achieve this through “ballooning,” where they release long silk strands into the air, catching wind currents to travel considerable distances. Others disperse by “bridging,” spinning a silk line between two points and walking across. These methods help them find new territories and reduce the likelihood of cannibalism among hungry siblings.
Spiderlings are born with instinctual abilities vital for their survival. From a very young age, they can construct miniature webs to capture prey or create shelters. They also possess the innate capacity to hunt small insects. As they grow, spiderlings independently undergo multiple molts, shedding their rigid exoskeletons to accommodate their increasing size.
When Moms Stick Around
While independence is common, some spider species exhibit maternal care extending beyond egg protection. These exceptions demonstrate varied evolutionary strategies to enhance offspring survival. Subsocial behavior, where offspring remain with their parent for a period, has evolved independently multiple times in spiders.
Wolf spiders are known for their unique maternal investment. The female carries her spherical egg sac attached to her spinnerets, guarding it. After the spiderlings hatch, they climb onto her back and remain there for about two weeks, clinging to specialized hairs. During this time, the mother continues to hunt and protect her brood.
Nursery web spiders also show dedicated care. The female carries her egg sac in her jaws until the spiderlings are ready to hatch. She then constructs a “nursery web,” a tent-like silken structure, where she places the egg sac and guards the newly emerged spiderlings for about a week before they disperse. In some social spider species, like Stegodyphus, multiple females and their offspring live in communal webs, cooperatively hunting and sharing food through regurgitation. This shared care can involve unmated females contributing to the colony’s young.