Crab spiders can be hard to find, but they are definitely around. The reason they can be hard to find is that most crab spider species are able to camouflage themselves with their surrounding areas. Also all of the species of crab spiders resemble crabs; hence their name. Physically the most distinctive crab like characteristics the crab spider has are their two front legs, angled outward and flat bodies. Also the movement of the crab spider mimics the movement of crabs. They walk forwards, sideways and backwards like crabs.
Crab spiders in general have neutral coloring, such as light brown to gray tones. The coloring of the crab spider allows them the ability to camouflage themselves to fit into their surroundings. Their shape, flat body and small size, averaging half an inch or smaller, can make them appear to be bird droppings. They can appear in multiple locations like bird droppings, for instance on the sidewalk, patio, roof tops, tree branches and many more locations, anywhere bird droppings can be found. This odd ability to disguise themselves as bird droppings actually gives them an advantage when hunting for food.
Even though the crab spider is smaller in size its two longer front legs make it appear to be larger than it’s described. The crab spider’s eyes are all small and act as motion detectors, which comes in handy when they are looking for prey. Crab spiders are able to crawl up places like trees, walls and posts. During the day, crab spiders sleep in an area where they blend well in order to stay out of view of predators. Once the sun falls, crab spiders will move around to find a hunting spot, or they may hunt from the location where they’ve been resting.
The hunting style of crab spiders is unique in that they will ambush their prey rather than chasing it down or like most other spiders they do not put a web up to trap prey. They will sit and wait in an area where they can camouflage themselves, i.e. grass, flowers, tree bark, fruit, foliage or even cracks and crevices in buildings until they can see their prey. Once an insect of their liking passes their path they will attack. For the most part crab spiders eat small- to medium-sized insects, including butterflies, ants, flies, mites, and bees. When a crab spider has caught its prey, it paralyzes it with its venom and is able to hold it down with its two larger front legs. The venom in the crab spider is powerful; it is believed they are cousins to the brown recluse spider who is very venomous. Yet, the venom of the crab spider is only effective on its prey and not people, unless a person is allergic.
The crab spider is not known for being harmful to people, but that doesn’t mean a crab spider will never bite a person. If you are bitten by a crab spider it can be very painful and can be dangerous if you are allergic to the crab spider’s venom. If you were to be bitten by a crab spider it would probably happen while you are outdoors. Crab spiders are not usually found inside homes unless they are looking for food or have been brought inside by accident. While outdoors the crab spider can be considered beneficial because it eats other insects, but that doesn’t mean you want them all over your yard. Plus there are the risks of your pets being bitten if they were to disturb a resting crab spider.
Another thing to consider, like many pests that can be found in or around your home, is that these spiders reproduce, so if you find one or two you always want to do a thorough check of the surrounding areas for eggs and or babies. The crab spider’s eggs are deposited into two silken sacs, and are joined together in the center. The female will put her sac somewhere safe and usually stays near by to protect it from predators. The hatch time for the eggs depends on the environment they live in. Crab spiders can be found anywhere in the U.S. although they prefer hot and dry climates like Arizona. Once the eggs hatch the baby crab spiders look like adults just much smaller in size. Then they will molt multiple times before becoming adults. The crab spider’s life spans average about a year, and rarely lasts longer.
Always be aware of your surroundings especially outside of your home.
Images courtesy of www.creativecommons.org