SPIDERS | BOISE, ID And metro area

Most spiders found in Idaho are relatively harmless. However, there are a select few to be wary of. Learn about the most common Idaho spiders below!


Wolf Spider

Wolf Spider Appearance

Wolf spiders are moderate to large in size (1/4" to 1" long) with dark brown and slightly hairy bodies.

Wolf Spider Behavior and Diet

Typically, wolf spiders can be seen living close to the foundation on the exterior of your home in window wells, around landscaping rocks and retaining walls. They commonly hunt during the day or at night when it is warm. Wolf spiders eat crickets, flies, cockroaches and beetles. They can be alarming because of their large size and rapid movements.

Wolf Spider Reproduction

Female wolf spiders produce egg sacs that spiderlings emerge from. The spiderlings go through a series of stages before becoming adults.


Yellow Sac Spider

Yellow Sac Spider Appearance

Yellow sac spiders are small to medium sized (1/5" to 2/5" long) and yellowish or light colored.

Yellow Sac Spider Behavior and Diet

This species of spider is normally found on foliage or the ground. Yellow sac spiders hunt at night, feed on small insects and hide during the day in a silken tube or sac, from which they take their name. Outdoors, yellow sac spiders will usually roll up leaves into a tube, or choose to live under stones. Inside homes, yellow sac spiders are found in a variety of places, including high-up on walls, near ceilings.

Yellow Sac Spider Reproduction

Yellow sac spiders will breed in early summer. The females tend to mate only once and produce up to five egg sacs with each sac containing approximately 40 eggs.

House Spider


House Spider Appearance

A common type of spider found indoors is the American house spider, also called the common house spider. It is grayish to brownish with chevron-like markings on its abdomen and a body length of over 1/4 inch long.

House Spider Behavior and Diet

The house spider is known for making a loose tangle of web in secluded and undisturbed areas of the house such as basements and crawl spaces. The webs are designed as a trapping tool for prey. Though the house spider primarily consumes insects, they also eat rodents, other large spiders, small reptiles, etc.

House Spider Reproduction

Female house spiders can produce as many as 250 eggs in each sac. The lifespan of a house spider can be up to 1 year.


Brown Recluse

Brown Recluse Appearance

Adult brown recluse spiders vary in color from a dark brown to a yellow. Adults can grow to 3 to 4 cm in length.

Brown Recluse Behavior and Diet

Brown recluse spiders are known to be a shy species of spider and do not bite unless provoked. They are typically found in dark, sheltered places such as barns, basements, etc. The brown recluse spider is a hunter; therefore, they do create webs to catch their prey.

Brown Recluse Reproduction

Female brown recluses can produce one to five egg sacs that contain upwards of 300 eggs. The eggs take about a month to hatch, and full development can take a year.



Black widow Appearance

Black widow spiders are typically black with two reddish triangular markings usually joined to form a reddish hourglass shape on the underside of their abdomen – their most recognized feature. Females are occasionally brownish black. Most black widow spiders are 3 to 10 mm long, with females being larger than males.

Black widow Behavior

The animals most at risk from the black widow's bite are insects—and male black widow spiders. Females sometimes kill and eat their counterparts after mating in a macabre behavior that gave the insect its name. Black widows are solitary year-round except during this violent mating ritual.

Black widow Reproduction

Black widow mating occurs in springtime into early summer. In some cases, black widow females consume males after mating, feeding on them as sources of nutrients needed for egg fertilization. Female black widow spiders can produce several egg sacs in summer months. These sacs are tightly woven, silken cups and are protected fiercely by the female until they hatch.


Cellar Spiders

Cellar Spider Appearance

Cellar spiders are 1/3 inch long, pale gray to light tan in color and have long delicate legs (resembling the daddy-longlegs).

Cellar Spider Behavior and Diet

Cellar spiders are common in dark, secluded places such as crawlspaces, basements, and cellars (as the name implies). Like the cobweb spiders, the cellar spiders build a loose, irregular web in corners near the ceiling or floor to catch its prey.

Cellar Spider Reproduction

Different from most other spiders, cellar spiders breed throughout the whole year. Due to always being the move, the female cellar spider carries its eggs wrapped in a silk net in between her jaws.


Orb Weaver Spiders

Orb Weaver Appearance

The orb weaver spider can range in size from small to large (1/8- to 1-inch long) and are found in a variety of colors, some being brightly colored. Orb spiders have large, swollen-looking abdomens, including some that are oddly shaped. Despite their large size and bright coloration, orb weaver spiders are not dangerous.

Orb Weaver Behavior and Diet

Orb weaver spiders are common spiders outdoors in gardens, fields, and landscapes. They are rarely found indoors. The orb weaver spiders make the familiar "typical" spider web of concentric circles and radiating lines.

Orb Weaver Reproduction

The female orb weaver is substantially larger than the male. That said, it is common for the male to be the female's first meal right after mating. The females will produce about one or more egg sacs with each sac containing upwards of several hundred eggs.

SPIDERS | BOISE, ID ANd metro area

Does your home or business have spider infestation problems? EcoCity Pest can help! As the leading Boise area exterminator, our technicians will take care of your spider problems efficiently and effectively. Don't wait, schedule an appointment online or give us a call at (208-901-6009 today!

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