Spiders are one of the most widely distributed groups of animals, adapting to almost every environment on Earth, from dense tropical rainforests to arid deserts and human homes. This versatility allows them to persist in virtually every ecosystem where insects and other small arthropods exist.
Global and Environmental Habitats
Spiders have successfully colonized nearly all of the planet’s terrestrial biomes, from the highest mountain peaks to the deepest caves. In forested environments, they occupy various vertical zones, with some species residing high in the tree canopy while others build webs closer to the forest floor. Many spiders live concealed under loose tree bark, within leaf litter, or in the soil, utilizing these microhabitats for shelter and hunting.
Many species are highly specialized to thrive in more extreme conditions, such as the burrowing spiders of grasslands that create silk-lined tunnels for protection and ambush hunting. Desert spiders have evolved strategies like nocturnal activity or specialized “sand-dwelling” behaviors to avoid the intense daytime heat and aridity. Even aquatic environments host spiders, with nearly one-fifth of all spider families having species associated with freshwater or saltwater habitats.
Semi-aquatic types, like fishing spiders, use the water’s surface tension to detect and capture prey, including small fish and insects. The fully aquatic diving bell spider, found in Europe and Asia, creates a submerged, silk-spun air bubble that functions like a miniature gill, allowing it to remain underwater for extended periods. Some marine-associated spiders live in intertidal zones, surviving tidal inundation by trapping air bubbles or retreating into airtight nests.
Common Indoor and Urban Locations
Spiders often enter human-built environments because these structures offer stable microclimates, protection from predators, and a steady supply of insect prey. Within a home, they favor dark, undisturbed, and cluttered areas that mimic their natural hiding spots. Basements, attics, and crawl spaces are particularly attractive due to their consistent temperature, relatively high humidity, and low human traffic.
Inside living spaces, spiders are frequently found in the upper corners of rooms and behind furniture, which provide excellent, sheltered locations to construct webs. Closets, storage boxes, and areas beneath sinks also create ideal habitats, offering both darkness and a source of moisture. They are often observed near window frames and doorways, strategically positioning themselves to catch insects that are drawn to light or enter the dwelling.
The exterior of urban structures also supports large spider populations, utilizing man-made features for shelter. Spiders commonly reside under eaves, in cracks within the foundation, and inside sheds and garages. Woodpiles, which offer a dense collection of sheltered spaces, are common nesting sites for various species. These urban and indoor locations provide the shelter and food resources that spiders require.
Activity Cycles and Seasonal Changes
A spider’s visibility is largely determined by its activity cycle; many species primarily operate under the cover of darkness. Most web-building spiders are nocturnal, repairing or constructing their snares at night to capture insects active after sunset. Other groups, like the highly visual jumping spiders, are diurnal hunters and are more frequently seen during daylight hours.
Seasonal fluctuations also dramatically influence where and when spiders are encountered, especially in temperate regions. Spider activity increases during the warmer months of spring and summer, as higher temperatures stimulate their metabolism and increase prey abundance. This is the period when females are most focused on feeding, web-building, and egg-laying.
The late summer and early autumn often lead to a noticeable spike in sightings as many species reach maturity and the mating season begins. Male spiders become particularly active and wander widely in search of females, which often brings them into greater contact with humans and sometimes indoors. As temperatures drop in late autumn, many spiders seek sheltered spots to overwinter, either by finding refuge indoors or entering a state of reduced metabolic activity, known as torpor, in secluded outdoor locations.