Jumping spider            Brown Recluse    Some thing        Orb-weaver     what appears to be a crab spider "ballooning"

Disclaimer: Most spiders cannot be identified by just the naked eye, they must be assessed by an expert, under a dissecting microscope.  The University of Wyoming Extension recommends that if you are unsure of the identity of a spider that you capture it and send it in.  Instructions as to how to properly send in a spider and where to send it, see capturing methods.  All spiders have venom; most venom does not harm humans, however there is always a possibility that a person could be allergic to one venom and not another.


Identify Your House Spiders!

If you really get into this, I would suggest getting one of those small containers with the magnifying glass in the lid; it will help you see some of the smaller identifying characteristics.

Common Spiders Found in the Wyoming House


Common Name and (Order) Picture Examples (Species in each order can vary greatly in shape, size and colors) Major Identifying Characteristics (species may vary) (size only refers to body length, not leg span)  

Eye Patterns (a good way for a fast identification)

Webs (some webs are good indicators of the type of spider)  

Are they harmful or beneficial to us?

Jumping Spiders






Size: between 0.2" and 0.7"

Behavior:  'jerky' movements, appears to look at you curiously, sometimes cocking to one side; males (see 8-legged facts) 'drum' their first pair of legs on the ground

Appearance: Most appear to be very fuzzy-looking; some smaller ones not so much.  Usually compact/stout. Some are black with white or yellow stripes, others are very colorful-from silver to bright, shiny green.

Found: often on walls, but really anywhere.


They mostly hunt, so they have no real need of a web.  They have the best eyesight out of the spiders and a very acute sense of touch (vibrations)



Jumping spiders are harmless and they do not readily bite even when handled.

Not only are they beneficial to us, but they are also very entertaining to watch!


Wolf Spiders








Size: adults 0.6" to over 1.0" Leg span: up to 4.0"

Behavior:  Very fast runners.  Some species may be aggressive if cornered. Females can be seen carrying egg sac behind her and the spiderlings will be  seen riding on her back for a while.

Appearance: Very 'leggy'; legs longer than body. They have spiky-looking hairs on their legs.  Colors very from dark brown to tan to light grey.  usually has stripes running the length of body.  One of the largest and most common spiders found in and around Wyoming.

Found: usually on the floor in basements, closets and outbuildings. 



They are known for their ability to track and hunt prey.  They do not use webs to catch prey.




Wolf spiders are shy, but when cornered, will bite.  Their bites have been known to be irritating and somewhat painful.   Sometimes a red welt will form for a couple of days, but then go away.



Nursery Web Spiders




Size: 0.4"- 1.0"

Behavior:  Similar behavior to wolf spiders.  Females can be seen carrying egg sac in their jaws. This is a good way to distinguish them from wolf spiders.  Some have been known to run over the surface of water.

Appearance:  Similar to wolf spiders, except their eyes are more equal in size.

Found:  On floors, outbuildings

They don't really make webs, except for their egg sacs.  They hunt like wolf spiders.





They are generally not harmful to humans.  They aren't as aggressive as wolf spiders when cornered.  Their bites are probably similar to wolf spider, but this is only an educated guess.


Daddy-Long-Leg or Cellar Spiders




Size:  0.05" to 0.3"

Behavior:  Almost always found hanging upside-down.

Appearance:  Very spindly, usually opaque cream or tan color with a darker body.  Very delicate-looking.

Found: on delicate webs in upper corners and usually in dark places light closets and basements.


They are known for their chaotic and delicate looking webs usually found in corners.



These spiders are not harmful to humans.  In fact, they have a similar niche to black widows, which means the more cellar spiders you have in your house, the less less likely you are to have black widows!
Funnel Web or Grass Spiders


Size: 0.4" to 0.9"

Behavior:  Usually found near or in their funnel-shaped web.

Appearance:  They're a bit similar to wolf spiders in appearance.

Found: In the grass, or dark places like basements, closets, behind furniture.

Just like their name says- their webs are usually very distinctly funnel-shaped.

Most of these spiders are mot harmful to humans, however see below for the hobo spider that is in this family.


Top-Common House Spider

(Tegenaria domestica)

Bottom- Hobo Spider

(Tegenaria agrestis)

Size:  Both are around 0.5"

Behavior: found on the floor and in dark places like old shoes

Appearance: Common House Spider- has faint bands around legs

Hobo Spider- lacks bands around legs

Found:  Common House Spider found in Wyoming

Hobo Spider Not found to be in Wyoming


Male spiders do not make webs.  These are usually the ones wondering about and are the ones that humans come in contact with most.



The Hobo Spider is considered harmful to humans and is very willing to bite.  The common house spider, which is often mistaken for the Hobo, is not.





Size: 0.1" to 1.0"

Behavior:  They are usually found hanging on their webs.  When disturbed, some will bounce on their webs.

Appearance:  Out of all of the spiders, the orb-weavers are the most diverse of shape size and color, but hey tend to be bulky and intricately patterned with colors. Some even have angular 'butts' (abdomens) Their webs are the best way to quickly identify them.

Found: usually outside, however, they may make webs just about anywhere.

Orb-Weavers are the poster children of the web-making world.  Most make the signature flat spiral web.

Orb-weavers vary greatly, but for the most part they are benign and gentle. 




Brown or Recluse Spiders



Size: 0.4"-1.0"

Behavior: May be aggressive if cornered.

Appearance: Legs are not spread to the side, but rather close and upright to the body.  Tan to medium brown color. may have a violin-shaped dark patch on the front part of the body (see top of page, 2nd picture to the left)  The eye pattern is a good indicator

Found:  everywhere in the home. 

6 eyes found in 3 pairs

Recluse spiders make sticky sheet-like webs to catch prey.




Some species of recluse have bites that  may cause local necrosis (mainly L. reclusa), however, not all brown spiders are harmful. 
Brown Recluse Spider

(Loxosceles reclusa)  

Size: Around 0.5"

Behavior: May be aggressive if cornered

Appearance:  light yellow to light tan.  violin on back may be hard to see- this is NOT a good indicator.

Found:  Not able to survive in Wyoming  climates.  Native to South Central U.S.


 6 eyes found in 3 pairs

They make sticky, messy sheet-like webs. 



Considered harmful to humans, killing the tissue in the area of its bite.  See bite page for more information.


Comb-Footed and Cobweb Spiders (includes Widows)





Size: 0.1"- 0.6" Widows are the largest

Behavior:  Usually found hanging upside-down on or near web

Appearance:  Almost all of them can be identified by their globular abdomen "backside."  Poisonous spiders in this group do not always look like the stereotypical black widow, but a generally those that do are the most damgerous.

Found: in crevasses, corners, under objects



Their webs are very chaotic looking, and are generally built in corners and dark crevasses.



Most of these spiders are harmless to humans, however some are definitely harmful; see next row.



Black Widow-top right

(Latrodectus mactans)

Northern Widow-top left

(Latrodectus variolus)


Size: Females adults are 0.5" to 0.6"  juvenile and male spiders are much smaller

Behavior:  Almost always found hanging upside-down.  Females are more aggressive when protecting spherical egg-sac.

Appearance:  Black Widow- black with red hour-glass on "belly" ventral side.  Northern Widow- black with a broken red hour-glass on ventral side.  juvenile females are tan with a striped abdomen 'backside'

Found: in crevasses, corners, under objects, and in unused prairie dog holes



The web is very chaotic webs and is usually built in dark places like corners, crevasses, and especially prairie dog holes.  The white ball-like egg sac is guarded by the female.



The black widow is the most well-known spider in this group, but both the Black and Northern Widows' bites can cause extreme pain and very rarely death. See bite page for more information.


Sac Spiders




Size: 0.2"- 0.5"

Behavior: They like to hunt for flying insects around light-fixtures. 

Appearance: Tan to pale yellow, usually with a lighter-colored 'backside' abdomen

Found:  Usually on walls and around light-fixtures.


May be found in tight crevasses, in silk tube-like webs used for rest, not to catch prey.



The bite of the yellow sac spiders has been mixed up with the brown recluse bite, but not all sac spiders are harmful.  See bite page for more information.


Ground Spiders




Size: 0.4"- 0.6"

Behavior:  usually live and hunt under objects

Appearance:  Usually a black or dark brown.  Probably the best way to identify these spiders are by their elongated, slightly flattened abdomen (back-end), and their

Found:  in storage boxes, firewood, landscape rocks



They don't really make webs; they mainly hunt.



They have not been reported to be harmful to humans.



Crab Spiders







Size:  0.1" to 0.5"

Behavior: They are named because they hold their legs similar to a crab.  They are usually still, and do not readily move even when disturbed.

Appearance:  They are a bit crab-like in appearance.  Many found in Wyoming are bright yellow, white, and may even have bright red markings.  Some have the ability to modify their color.

Found:  Usually on flowers, however, they can get accidentally carried into the home on clothing.




Crab spiders don't spin webs to catch their prey, rather they wait very still, usually on flowers or other plant parts, for flying insects to come by, and then they pounce on them.




Crab spiders are  not know to be harmful to humans, and will not readily bite even when provoked.









Still can't find an example that fits your spider? There are many 8-legged creatures out there that may look like spiders, but are not in fact spiders.  Try some of these spider-cousins, but note that not all of them are found in Wyoming:

Fun things found in the Iraqi deserts!  Sunspiders (not real spiders) are fast, fearless, and frightening when found in your sleeping bag!



Back to the UW Extension SpiderWeb Main Page