Most common household spiders are harmless, though there are a few species that can inflict venomous bites strong enough to harm pets and people. With thousands of species of spiders known around the world, it can be hard to know which are simply a nuisance and which to avoid. Let’s take a look at eight common spider types found in the United States and sort out the harmless from the harmful.

AREN’T ALL SPIDERS DANGEROUS?

Contrary to popular belief, no spiders are actually poisonous. They are, however, nearly all venomous. For a spider to be considered poisonous, they’d have to cause medical harm when ingested. Since most of us aren’t adding spiders to our dinner plates, our concerns revolve around the toxicity of their venomous bites.

Exposure to spider venom through bites results in varying degrees of reactions, but most spider’s venom is only toxic enough for the small bodies of their prey. Better still, most spiders won’t attempt to bite humans at all, and if they do, most of us will hardly even notice.

COMMON TYPES OF HOUSE SPIDERS THAT ARE HARMLESS

There are many types of spiders in our homes. Some are harmless and non-poisonous, while others can be dangerous if they bite or sting. Here are some common house spider species that are harmless:

• Cellar spiders
• Common house spiders
• Hobo spiders
• Jumping spiders
• Sac spiders
• Wolf spiders

CELLAR SPIDERS

Cellar spiders are commonly referred to as “daddy longlegs” for their thin, long legs. These lanky spiders have a single small body with muted colors of light brown, grey, or tan that makes them a little tricky to spot. However, cellar spiders typically leave evidence of their occupancy. These spiders are responsible for some or all of the unmethodical, messy-looking cobwebs found in our corners and windowsills.

As their name suggests, cellar spiders reside in the basements, garages, and cellars. They prefer to hide out in enclosed spaces, but catching a cellar spider crawling across the ceiling, along baseboards, or hiding out in corners is a common occurrence. Because they eat a variety of other insects and arthropods, some even consider them beneficial pests. Cellar spiders aren’t known to bite people, so fear not if you encounter one.

COMMON HOUSE SPIDERS

The spider you’re most likely to encounter indoors, house spiders are really just an environmental annoyance to humans (albeit a creepy one). House spiders are small arachnids, measuring between ¼ to ½ inch when fully matured. Their bodies are generally a warm, golden brown or tan color with a mottled, speckled pattern on their abdomen.

House spiders, like cellar spiders, are also considered tangle-web spiders for the messy cobwebs they build in corners, under eaves, in closets, and anywhere with two adjacent walls, beams, or objects. Alfred Q., Moxie customer in Utah, explained that he’d frequently find these spiders—and their webs—in his often-chilly basement. His field expert dewebbed the area and treated the baseboards, resulting in far fewer of these eight-legged invaders.

The venom from these spiders is nothing to worry about, and they will most likely try to flee when they catch sight of potential danger from humans, pets, and creatures that tower over them.

HOBO SPIDERS

These spiders were once called “aggressive spiders,” but that isn’t due to their danger to humans. While they’re swift and ominous looking, they were named because of a misinterpretation of their Latin name, agrestis, which actually means “of the field.” Hobo spiders are typically found outdoors, and their webs can be funnel-like and built most often beneath or within objects. Hobo spider webs are often discovered inside of bricks, under wood, within shrubs, or indoors beneath beds or under piles in the garage.

Hobo spiders are frequently misidentified, most often being mistaken for other funnel-weaving spiders in the same family. These brown spiders appear very hairy on both their legs and bodies, with noticeable chevron markings on their abdomen. At an average of ½ inch with long legs, they look intimidating and may actually bite if threatened, but treatment is no more complicated than any other bug bite.

JUMPING SPIDERS

Aptly named, these spiders can jump impressive distances to catch their prey. While their bodies produce silk to wrap their egg sacs and hang from ceilings, they aren’t typically web builders and rely on their mobility and quick reflexes to pounce on their meals. They’re even considered friends of green-thumbed humans, as they love to hang out on foliage and feed on many harmful garden pests.

The appearance of jumping spiders varies quite a bit. Some are black with white, striped markings, while others are brown or iridescent. They’re most recognizable for the two enlarged eyes in the center of their heads, their noticeable jaws, and their hairy bodies. These spiders are active daytime hunters, so keep an eye out in the sunnier hours for these arachnids. Bites from jumping spiders are uncommon and, at worst, mildly painful.

SAC SPIDERS

Commonly called yellow sac spiders, these arachnids can actually appear cream or beige colored, too. Sac spiders have tufts of brown or black fur on the ends of their legs that look like they’re sporting small socks or shoes. Sac spiders don’t build webs to catch their prey and instead spend the night hunting for small insects and eggs to munch on.

It’s not uncommon to find these spiders on the ceiling or in a corner. Sac spiders are drawn to clutter both indoors and outdoors. A pile of leaves, a dusty corner, and an enclosed space are all places sac spiders can be found. Sac spider bites can range from slightly irritating to as painful as a bee sting. Still, their venom isn’t likely to cause anything more than an annoying bug-bite reaction for a day or so.

WOLF SPIDERS

These spiders were once believed to hunt in packs as their canine namesake suggests. While they don’t congregate to hunt, they are very swift and aggressive toward their prey, ambushing their meals from obscured hiding spots. Wolf spiders are not web-builders and are even often mistaken for small tarantulas.

Wolf spiders can be pretty bold. It’s common to catch sight of one of these large spiders out in the open at ground-level where they reside. Wolf spiders have shorter legs than other types, and their hairy bodies are typically tan or brown in color. Bites from these spiders can be painful, but rarely happen unless they’re handled directly.

SPIDERS TO LOOK OUT FOR

BROWN RECLUSE SPIDERS

Brown recluse spiders are potentially dangerous arachnids. Their venom is considered necrotic/cytotoxic, meaning that it causes death to living cells. Necrotic venom damages or kills tissue around the bite site, causing unpleasant reactions like blisters or lesions. Brown recluse venom affects the human body in stages, and reactions won’t begin for hours or even days after being bitten. Some bites may only result in a painful lesion, while others can cause severe reactions like fever, chills, nausea, scarring, and tissue death.

These spiders are variable in size. Most often, they are about the size of a quarter, and sometimes look more tan than brown. They are nicknamed “fiddle back” spiders for the violin-shaped markings on their abdomen. Brown recluse spiders shed their skin, and molted casings can clue homeowners in to their presence. Most often, they reside outside in wood piles or collections of debris, but they can be transported inside on firewood, bags, and boxes.

BLACK WIDOW SPIDERS

Though their bites are rare, they’re one of the most harmful—and can be potentially fatal. Black widow spider bites aren’t even typically painful at first, which makes them tricky to track. Toxins from black widow spider venom affect the nervous system, and symptoms most often resemble the flu. More severe reactions result in rigid muscles, sweating, severe pain, and patchy paralysis.

Luckily, black widows are timid arachnids with markedly unique features that make them simple to identify. Their bodies are usually jet-black and shiny all over except for a distinct red marking on their abdomen. A well-fed spider can appear brown due to their enlarged black body becoming stretched and full. Widow spiders nest primarily outside within clutter and build their webs in doors, near vents, and in spaces where traffic from other insects is likely.

Most spiders aren’t going to harm you and are non-poisonous, but you still don’t want them as houseguests. If you’ve spotted a spider (or if spider identification isn’t your idea of a good time), contact our team of trained experts and we’ll take it from there.