Crab spider
Family Thomisidae (many species, e.g., Misumena vatia — Goldenrod Crab Spider)
Quick ID
Small to medium-sized spiders with wide, flattened bodies and long, sideways-pointing front legs that resemble a crab’s claws. They often sit motionless on flowers, perfectly camouflaged in white, yellow, or green.
Ecological Role
Ambush predator.
Instead of spinning webs to catch prey, crab spiders hide on flowers and snatch visiting insects—often pollinators like bees, flies, and butterflies.
They help balance insect populations.
At-a-Glance
Size: ⅛–½ inch (females larger than males)
Colors: White, yellow, green; often patterned
Body Shape: Wide, flat, crab-like stance
Hunting Style: Ambush predator, no web
Diet: Bees, flies, butterflies, and other insects
Social? No—solitary
Where to Find It
Range: Found across North America and worldwide.
Habitat: Flowering plants, garden beds, meadows, forest edges.
Nesting: No web traps—just silk retreats for molting or egg sacs.
Look-Alikes
Flower Spiders: Other species in the same family, also found on blooms.
Small true crabs (at a glance): Their sideways stance and big front legs can trick the eye!
Why It Matters
Though they sometimes take pollinators, crab spiders are part of the natural system that keeps insect populations healthy and diverse. Their camouflage skills also make them fascinating ambassadors of predator–prey adaptations in the backyard.
Safety
Harmless to people. Their venom is only strong enough for insects, not humans. They don’t bite unless handled roughly.
Fun Fact
Some crab spiders can change their color (white ↔ yellow) over several days to better match the flower they’re hunting on.
Dig Deeper
Curious for more? Read the blog.
Recommended Book References
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