Flattie, Wall Spider, Moon-Eyed Spider, Crescent-Eyed Spider
Selenops sp.
Selenopidae (Wall Spiders), Order Araneae. Characterized by an extremely flattened body and a specific semi-circular eye arrangement.
Physical Description
Extremely dorso-ventrally flattened body (hence the name 'Flattie') designed for squeezing into narrow crevices. The cephalothorax is broad and the abdomen is oval-shaped. They have a sprawling, crab-like leg posture.
Size Estimate
Body length 5-20mm depending on species and age; leg span can reach 2-3 inches. This specimen appears to be an adult or sub-adult based on proportions.
Coloration & Markings
Mottled brown, gray, and tan camouflage patterns. These cryptic markings allow them to blend perfectly with tree bark or stony surfaces. Leg banding is typically prominent.
Web Type
Non-web builder. These are active hunting spiders that use speed and ambush tactics rather than silk traps to capture prey.
Eye Arrangement
Unique semi-circular (crescent) arrangement of six eyes in the front row and two larger eyes behind. This provides a nearly 360-degree field of vision.
Leg Characteristics
Sprawling (laterigrade) legs that allow for rapid side-to-side and backwards movement. The legs are heavily banded with dark and light pigments and possess small spines.
Venom & Safety Information
Venom Information
Possess a mild venom used to immobilize small insects. It is not considered toxic to humans or domestic pets.
Medical Significance
Harmless. Bites are extremely rare due to their speed and timid nature. A bite might cause minor localized redness and itching similar to a mosquito bite.
Safety Recommendations
No special safety measures required. If found indoors, they can be gently relocated using the 'cup and paper' method, though their speed makes them difficult to catch.
Habitat & Behavior
Habitat & Range
Found globally in tropical and subtropical regions. Often found on tree trunks, under flat rocks, or on the exterior and interior walls of buildings.
Behavior & Temperament
Incredibly fast; they are documented as some of the fastest-turning animals on the planet. They are shy, non-aggressive, and will almost always choose flight over fight when confronted by humans.
Diet & Prey
Generalist predators feeding on various small insects including flies, cockroaches, and moths. They use an explosive 'lunge-and-spin' maneuver to strike prey.
Seasonal Activity
Active year-round in tropical climates; in temperate regions, they are most visible during the warm summer and autumn months.
Description
The Flattie is a master of camouflage and speed. Its incredibly thin profile allows it to vanish into cracks barely wider than a credit card, making it a common but often unnoticed resident of homes and gardens.
Key Features
Extreme flat body, sprawling leg posture, mottled camouflage pattern, and the ability to move and turn with lightning speed.
Similar Species
Often confused with Running Crab Spiders (Philodromidae) or Huntsman Spiders (Sparassidae). It is distinguished by its flatter profile and unique crescent eye arrangement.
Life Cycle
Females produce a flat, disc-like egg sac that they often guard. Spiderlings emerge and look like miniature versions of adults. They can live for over a year in warm climates.
Ecological Importance
Highly beneficial as natural pest control, as they actively hunt cockroaches and other household and garden pests.
Conservation Status
Not evaluated by the IUCN, but generally considered common and stable throughout their native ranges.
Interesting Facts
A study found that Selenops spiders can turn 360 degrees and strike prey in about one-eighth of a second—faster than a human blink.
Photography Tips
Shoot from a top-down angle to emphasize the flat body and leg span. High shutter speeds are necessary if the spider is moving, and macro lenses help capture the unique eye layout.
Identified: 2026-06-12T21:00:32.809043