Montana is known for its natural beauty and is home to many state and national parks. Many types of wildlife thrive in Montana, including common spiders. You can spot all kinds of arachnids throughout the state, including large spiders, small spiders, and spiders that have some unusual habits.
Not only can you find spiders in the great outdoors, but there are also lots of spiders that can be seen inside homes! Whether you’re indoors or outdoors, these are some of the spiders you’re most likely to spot in The Treasure State.
10 Common Spiders in Montana
What kinds of spiders can you find in Montana? These 10 arachnids are some of the most common spiders in the state.
1. Southern Black Widows
Scientific Name: Latrodectus mactans
This spider is a deep black color with red markings that look like an hourglass. It strongly prefers outdoor habitats, such as tree stumps and wood piles, but can sometimes be seen in garages and sheds.
The black widow loves to eat fire ants, but it feeds on many other insects as well, like woodlice and mosquitoes. Not only is the southern black widow the most venomous spider in Montana, but it’s the only common spider in the state with venom that’s harmful to humans.
While bites are rarely fatal, they can cause severe symptoms, including stiff muscles, nausea, and difficulty breathing. These spiders sometimes hide in shoes, so it’s smart to shake your shoes before you put them on.
2. Orb Weavers
Scientific Name: Araneidae
Orb weavers are a large family of spiders that spin spiral-shaped webs. Many species are common in Montana, including star-bellied orb weavers, marbled orb weavers, cat-faced spiders, and shamrock spiders. You’re most likely to see these spiders in fields, forests, and in backyard gardens.
Female orb weavers tend to be much larger than males. For example, female star-bellied orb weavers are usually between 0.27 and 0.59 in, while males can be anywhere from 0.19 – 0.31 in. Some species, like the marbled orb weaver, have bright colors and distinctive patterns.
3. Candy-Striped Spiders
Scientific Name: Enoplognatha ovata
Even though this spider is native to Europe, it’s been introduced to many parts of North America, including Montana. True to its name, these spiders usually have stripes across their abdomens. It’s drawn to grassy environments and is frequently seen in backyards and gardens.
While these spiders rarely grow to be larger than 0.27 inches, they’re powerful predators that can feed on much larger insects. They catch their prey by spinning large, tangled webs. The candy-striped spider can be a major threat to other bugs, but it’s not dangerous to pets or humans.
4. Hobo Spiders
Scientific Name: Eratigena agrestis
Hobo spiders are very common in both central and western Montana. They like to hide in holes and cracks and can be found in a variety of habitats. In colder weather, they often take shelter in homes, which can lead to spider infestations.
These spiders produce funnel-shaped webs that often lead into a safe spot, like a crack or hole. Although hobo spiders do bite humans, they don’t have strong venom, and their bites usually aren’t dangerous. Male hobo spiders are more active than females and are more likely to bite.
5. Bowl and Doily Spiders
Scientific Name: Frontinella pyramitela
This sheet weaver spider is known for its unusual web! It builds a dome-shaped web above a horizontal web and uses both webs to catch gnats, flies, and other small insects. These webs can often be seen hanging from tree branches, where they may also collect leaves, twigs, and other types of debris.
In Montana, you’re most likely to see these spiders in wooded areas and in weedy fields. Most spiders are solitary, but males and females of this species are known to cohabitate. While they produce venom, they rarely bite humans, and their venom isn’t dangerous to humans or pets.
6. Parson Spiders
Scientific Name: Herpyllus ecclesiasticus
This medium-sized spider is commonly seen in Montana and is often considered to be a nuisance. It likes to hide beneath clothing and in bedding and will bite humans when it becomes trapped between fabric and human skin. While it’s generally nontoxic, its bites can be painful and can even cause allergic reactions.
These spiders are drawn to large, open regions and like to hide beneath rocks and logs. They like to hunt for food at night and frequently make their way inside homes. Parson spiders shed their skin as they grow, which is why molting is one of the most noticeable signs of a spider infestation.
7. Crab Spider
Scientific Name: Thomisidae
It’s very common to see crab spiders in Montana gardens. Some of the more common species include the ground crab spider, running crab spider, and deadly ground crab spider. Despite its name, the deadly ground spider is harmless and doesn’t pose any danger to humans or pets.
Most crab spiders are small, which can make them difficult to spot! These spiders rarely grow to be larger than 0.4 in. Crab spiders don’t spin webs and usually ambush their prey when it’s nearby.
8. Forest Wolf Spiders
Scientific Name: Hogna frondicola
The forest wolf spider can grow to be more than 2 in, making it one of the largest spiders in Montana. It’s a large, hairy spider that has long legs and a gray stripe along its abdomen. True to its name, these spiders are often found in wooded areas, but they can also be spotted in rocky regions.
While these spiders may look intimidating, they’re not aggressive, and their bites aren’t dangerous to pets and humans. Unlike most spiders, they have excellent eyesight, which allows them to hunt for prey without weaving webs. After they catch an insect, they usually inject it with venom and then mash it up so that it’s easier to eat.
9. Rabbit Hutch Spiders
Scientific Name: Steatoda bipunctata
These tiny spiders usually don’t grow to be any larger than 0.2 in. They have black bodies with reddish-brown abdomens, which sometimes causes them to be mistaken for black widows. Although rabbit hutch spiders are a part of the same family as black widows, they’re not dangerous and almost never bite humans.
The rabbit hutch spider has a strong preference for sheltered habitats and can often be found in garages and sheds. As its name suggests, it can also be found in animal pens like rabbit hutches! It likes to weave its flat web along the outside of buildings, where it catches pests like flies, wasps, and beetles.
10. Red-Spotted Ant Mimic
Scientific Name: Castianeira descripta
The red-spotted ant mimic is one of the most aggressive spiders in Montana, but thankfully, it’s far more aggressive towards insects than humans. Even though it has eight legs, it likes to mimic ants by walking on six legs and using its other legs as antennae. It uses this disguise to hunt ants and other spiders!
These spiders can be found in many habitats, including wooded areas and in parks. While they don’t spin webs, they do spin sacs that they sleep and lay eggs in. Usually, these sacs are located near an ant colony or are hidden under leaves or in bark cracks.