Tan Jumping Spider, Familiar Jumping Spider
Platycryptus undatus
Salticidae (Jumping Spiders), Order Araneae
Physical Description
A flattened, fuzzy body designed to hug tight to vertical surfaces. The cephalothorax is broad and the abdomen is elongated with a distinctive undulating pattern. They are covered in fine, dense hairs.
Size Estimate
Adult body length typically ranges from 8mm to 13mm. This specimen appears to be an adult female based on the broader abdomen and markings.
Coloration & Markings
Mottled brown, gray, and white. The most diagnostic marking is the tan or grayish undulating 'v' or 'chevron' pattern running down the center of the abdomen against a darker background.
Web Type
The Tan Jumping Spider does not spin a hunting web; it is an active hunter. It only spins silk for 'draglines' to catch itself during jumps and for silken retreats (pup tents) used for molting or laying eggs.
Eye Arrangement
Four pairs of eyes with the Anterior Median Eyes (AME) being very large and forward-facing, providing high-resolution binocular vision. The remaining eyes are smaller and arranged along the sides of the cephalothorax.
Leg Characteristics
The first pair of legs is often thicker and used for grasping prey. The legs are generally short, stout, and hairy with dark banding patterns and specialized pads (scopulae) that allow them to walk on smooth vertical surfaces.
Venom & Safety Information
Venom Information
Neurotoxic venom specialized for paralyzing small insects. To humans, the venom is very weak and is not considered medically significant.
Medical Significance
Harmless to humans. Bites are extremely rare and usually occur only if the spider is pinched. Symptoms are typically less severe than a bee sting, involving minor localized redness or itching.
Safety Recommendations
No special safety measures required. If found indoors, they can be safely relocated using the 'cup and paper' method, though they are beneficial houseguests for controlling flies.
Habitat & Behavior
Habitat & Range
Found throughout North America, particularly in the Eastern United States and Canada. They are very common on vertical surfaces like tree trunks, fences, and the exterior walls of houses.
Behavior & Temperament
Highly intelligent and curious. They are active hunters that stalk prey with precision. They are generally very docile toward humans and will often tilt their heads to look at people, showing a high level of visual awareness.
Diet & Prey
Generalist predators targeting small insects like flies, moths, and mosquitoes. They use their exceptional vision to stalk prey and then pounce from a distance, biting to deliver venom.
Seasonal Activity
Most active from spring through autumn. They often overwinter as adults or sub-adults in silken 'hibernacula' hidden under bark or siding.
Description
The Tan Jumping Spider is one of the most charismatic spiders found near human habitations. Known for its flattened appearance and remarkable 'face,' it is a expert at blending into tree bark. Unlike many spiders that flee, this species often appears to observe its surroundings with keen interest.
Key Features
Flattened body profile; tan/gray undulating pattern on the dorsal abdomen; large forward-facing eyes; hairy mottled appearance.
Similar Species
Platycryptus californicus (found in Western North America) and various species of the genus Marpissa, which tend to be more elongated and less flattened.
Life Cycle
Females lay eggs in silken retreats often tucked under tree bark or shingles. They exhibit some maternal care, guarding the sac until spiderlings emerge. They typically live for about a year.
Ecological Importance
Significant natural pest control, especially for flies and other pests found on the exterior of buildings and garden structures.
Conservation Status
Not evaluated by IUCN, but considered common and stable throughout its range.
Interesting Facts
Each jump they make is assisted by a silk safety line. They have some of the best vision of any invertebrate, capable of seeing color and detecting movement from several feet away.
Photography Tips
Focus specifically on the large front eyes for a compelling 'portrait' shot. Side-profile shots are best for showing the flattened body shape; use soft, natural light to avoid blowing out the white and tan hairs.
Identified: 2026-06-10T16:06:20.892219