Crab Spider

The Crab Spider

In our surroundings innumerable insects and pests exists, and some of them are extremely dangerous for humans, spiders are one of them. The Crab Spider isn’t very dangerous, but it’s important to be educated about them when faced with an encounter. So let’s check some details about Crab Spiders.



a crab spider is crawling

Crab Spider

Crab spiders have a distinguishing crab-like body and their ability to move sideways and backward, just like crabs, gave them their name.

They possess wide, flattened bodies which have four pairs of legs. The two front legs are longer and stronger than others and are used for grabbing preys. They have the ability to see in all directions with help of their 8 eyes.

They can grow from 0.16 to 0.3 inches in length. Females are bigger in size as compared to males and usually have white, pale, yellow, or green colored bodies bearing red dots on the abdomen. Male crab spiders have dark-colored bodies and brown stripes cover their greenish-white abdomen.


Crab Spiders have a unique ability to camouflage. They change their body color and blend in the environment and look like fruits, flowers, leaves or even bird droppings; this way they deceive their prey and when it comes near them, they kill it.

They kill their prey by injecting venom but they aren’t known for biting humans because their small mouthparts are incapable to pierce human skin.

Female spiders lay eggs few days after mating and these are kept in connected silken egg sacs. Female spiders guard the sacs, till the young ones hatch out. During the entire tenure (up to 3 weeks) females don’t go out to eat and because of fatigue, they die within a short period after spider-lings hatch.


It’s not easy to detect crab spiders infestation in your house, as they have exceptional ability to put themselves out of sight.  The only way you can detect their presence is by sighting spiders themselves.


Crab spiders rarely infest indoors because they majorly feed upon mosquitoes, honeybees, butterflies, flies and other outdoor insects. But if you have a garden or lawn in your home, this could be housing crab spiders because of the abundance of insect prey available. From there, they can invade indoors as well.

Moreover, they can get inside your home by hitchhiking via your belongings, boxes, firewood, camping kit, etc.


Crab spiders aren’t dangerous for humans, in fact they help in controlling various pests in garden, but if their presence is unpleasant for you then you can try following techniques to eradicate them from your premises.

Seal the openings:

Seal the openings in your pipes, caulk the cracks in walls and remove the gaps in windows and doors; because usually crab spiders residing in your lawn or garden, make entry in your home through them.


Encourage the presence of songbirds in your yard. These birds feed upon such spiders and other insects and they not only will kill spiders but also reduce the chances of their presence by eating other insects and bugs.

Cleaning and vacuuming:

Ensure proper sanitation of your home, frequently remove crab spider nests and vacuum on a regular basis.

Gardens should be properly managed to destroy potential hideouts of spiders; regularly trim the unnecessary grass and remove debris, dead leaves and grass clippings. This will reduce the chances of presence of insects and ultimately restrict Crab Spiders’ activity.

Professional exterminators should be called in case of serious infestation especially around greenhouse.

Crab Spider Facts

  • Unlike common spiders, crab spiders don’t spin webs.
  • Their highly toxic venom can leave even large insects still.
  • Giant Crab Spiders can bite humans, but their bites aren’t harmful and will cause mild pain.
  • They are diurnal in nature, which means they are active at the day time.
  • They have a lifespan of 1-2 years.