Cave Spider Identification Guide
Identify cave spiders by their extremely long legs, pale coloring, and preference for dark, damp shelters.
Read the full Cave Spider encyclopedia entry →
Key Visual Features
Cave spiders are adapted to permanently dark environments, and their appearance reflects that lifestyle.
- Size: Body length usually 5 to 15 mm, but the legs are disproportionately long, giving an overall much larger span.
- Color: Pale yellowish-brown, tan, or light orange, often lighter than surface-dwelling relatives, since strong coloring is less necessary without sunlight exposure.
- Body shape: Small, rounded abdomen with a narrow cephalothorax and extremely long, thin legs.
- Eyes: Eight eyes, though some deep cave-dwelling species show reduced eye size compared to surface spiders.
- Movement: Slow, deliberate leg movements that help them navigate uneven, dark surfaces by touch.
Where and When You'd See One
As the name suggests, cave spiders favor dark, humid, enclosed spaces.
- Natural caves, mines, and rock crevices
- Basements, cellars, culverts, and similar dark, damp man-made spaces
- Often found hanging in loose, irregular webs near cave entrances or in corners
- Present year-round in stable cave or basement conditions, since temperature and humidity stay relatively constant
Similar-Looking Bugs
- Cellar spiders (daddy long-legs spiders) look similar with long thin legs but have a more slender, cylindrical abdomen and are common in ordinary indoor spaces, not just caves.
- Wall spiders have a flattened body rather than long, spindly legs and prefer open vertical surfaces over enclosed dark spaces.
- Wolf spiders are stockier, hairier, and hunt on open ground rather than lurking in dark, enclosed shelters.
- Comb-footed spiders have a rounder abdomen and shorter legs relative to a cave spider's elongated form.
Quick ID Checklist
- Extremely long, thin legs relative to body size
- Pale tan, yellow, or light orange coloring
- Small rounded abdomen
- Found in caves, mines, basements, or similarly dark, damp shelters
- Loose, irregular web near a dark entrance or corner
Frequently asked questions
What makes cave spiders different from other long-legged spiders?
Their pale coloring and preference for permanently dark, humid environments like caves, mines, and basements set them apart from surface-dwelling look-alikes.
Are cave spiders always found underground?
They favor dark, stable environments, which can include natural caves but also basements, cellars, and culverts with similar conditions.
How can I tell a cave spider from a cellar spider?
Cellar spiders have a more slender, cylindrical abdomen and are common in everyday indoor spaces, while cave spiders are more strongly tied to deep, dark, humid shelters.
Why are cave spiders so pale?
Living in permanent darkness reduces the need for protective or camouflaging coloration, so many cave-dwelling species appear lighter than their surface relatives.