Tarantulas are often perceived as dangerous and aggressive creatures due to their size and appearance. However, it’s essential to know whether these spiders are actually harmful to humans through their bites or other defenses.
Although tarantulas do possess venom and can bite, they generally pose no serious danger to humans. In fact, their bites are often compared to a bee sting in terms of pain and effects. When threatened, a tarantula will initially rear up on its back legs, exposing its fangs, and may even eject hairs from its abdomen that are coated with venom (source).
Varieties of tarantulas differ in their characteristics, and some examples include the common Rose Hair Tarantula and the Goliath Birdeater Tarantula. While the specific traits of each species may vary, these spiders share common behaviors and features, such as:
- Nocturnal habits
- Unique defensive behaviors (e.g., flicking hairs)
- Lifespans that can span several years
- Males having a shorter lifespan than females
Species and Distribution
- Tarantulas are a group of large, hairy spiders belonging to the family Theraphosidae.
- Over 900 different species are found worldwide.
- They primarily inhabit tropical and subtropical regions across South America, North America, and other areas.
- The Chilean Rose Tarantula is native to South America.
- The Goliath Bird Eater, one of the largest species, also comes from South America.
Sizes and Colors
- Tarantulas vary in size and color across species, with some being more vibrant than others.
- Sizes can range from around 3 to 5 inches (7.6 to 12.7 cm) to nearly a foot in leg span for the Goliath Bird Eater.
- Brown (Common Puerto Rican Brown Tarantula)
- Black and red (Mexican Red Knee Tarantula)
Behavior and Habitat
- Tarantulas are typically nocturnal predators.
- They don’t spin webs to catch prey, but instead use venom and silk to immobilize them.
- Tarantulas prefer living in burrows in the ground.
- Some create silk linings in their burrows, using it for protection and insulation.
Molting and Growth
- Tarantulas molt, or shed their exoskeleton, to grow larger.
- Molting occurs multiple times in a tarantula’s lifecycle, which can last several years.
- In captivity, some tarantulas may molt less frequently due to more stable conditions.
Pros and cons of molting:
- Pros: Allows for growth and repair of damaged exoskeleton.
- Cons: Tarantulas are vulnerable to predators during the molting process.
|Size||Large||Small to large|
|Molting frequency||Multiple times||Varies|
Tarantulas are not aggressive creatures, but they can bite if they feel threatened or provoked. However, most species of tarantulas rarely bite humans. When they do, it is typically a defensive measure rather than predatory behavior.
Pain and Venom Effect
The impact of a tarantula bite can vary greatly depending on the species involved. In general, the pain from a tarantula bite may be mild to moderate, similar to a bee sting. Some individuals may experience more severe pain, especially if they are allergic to the venom. Common symptoms include:
- Localized pain and swelling
- Redness around the bite area
- Mild itching
Tarantulas possess venom, but for most species, the venom is not harmful to humans and poses no serious danger. However, there are some exceptions, such as the Old World tarantulas, whose venom can cause more severe reactions.
Comparison of Tarantula Bites and Other Spider Bites
|Tarantula Bite||Typical Spider Bite|
|Pain||Mild to moderate||Moderate to severe|
|Venom||Usually mild; moderate in some species||Varies by species; can be dangerous|
In conclusion, tarantula bites are infrequent and often less dangerous when compared to other spider bites. Their venom is generally mild, but certain species might have more potent venom. People with allergies to the venom may experience more severe reactions.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Salt Lake City Brown Tarantula
Location: Salt Lake City
October 2, 2010 10:24 pm
My wife and I were hiking in the foothills just north of Salt Lake City in City Creek Canyon when we happened on this big hairy guy (or maybe gal). The Utah Museum of Natural History website has information on a Salt Lake City Brown tarantula. Could this be a SLC Brown?
Your Tarantula is beautiful. It matches a photo of Aphonopelma iodius which we located on BugGuide. or the Desert Blond Tarantula, Aphonopelma chalcodes, which is also pictured on BugGuide. BugGuide also has this information posted on the genus page: “The Aphonopelma of North American are poorly known. Although many species have been described few specimens can be properly identified either by using available keys or by wading through species descriptions . Most identifiable specimens belong to species found in Mexico or Central America that are easily recognized by unique color patterns, such as that of A. seemanni . Correct identification of specimens collected within the United States is often suspect since determinations must be based on the process of elimination using collection dates and locality data in combination with coloration, coxal setation, and metatarsal scopulation ” and the quote is attributed to http://americanarachnology.org/JoA_free/JoA_v25_n2/JoA_v25_p137.pdf. At the very bottom of the Spiderzrule Tarantula page we found a photo of the Salt Lake City Brown Tarantula and it is identified as Aphonopelma melanium. Interestingly, the Salt Lake City Brown Tarantula on the Utah Museum of Natural History website is identified as the first spider we mentioned, Aphonopelma iodius. It was found in Salt Lake City and it is a brown Tarantula, so we are content calling it a Salt Lake City Brown Tarantula.
Letter 2 – False Tarantula
Subject: Found near our garage
Geographic location of the bug: Fremont, San Francisco East Bay Area
Time: 03:13 AM EDT
Ok, came home after Thanksgiving dinner with the family to find this large spider/tarantula on the wall next to our garage door. It was around 2″ long, healthy, and didn’t seem to be aggressive at all. Temp was in the 50’s, warmer than normally this time of year. We do have some Tarantulas nearby, but this one seemed a bit different.
I can’t easily ID it but after some online searches have narrowed it down to these candidates:
Wolf Spider (Schizocosa mccooki or Pardosa ramulosa)
False Tarantula (Calisoga longitarsis)
California Tarantula (g. Aphonopelma)
How you want your letter signed: Cool but creepy
We are going to go with False Tarantula in the genus Calisoga which is pictured on BugGuide. According to BugGuide, there are: “5 species, all essentially California endemics” and their range is “Kern County north to Shasta County, Coast Ranges + Sierra Nevada. Some isolated populations in western NV.” Now we wonder if any of the spiders from California we have identified in the past as Tarantulas might actually be False Tarantulas.
Thank you Daniel! Was leaning towards this. We have found this spider a few times, but the first was on a box we had in our garage… that was coming from China. My first concern was, of course, an invasive species. We do have Zoropsis spinimana, an invasive Mediterranean Spider (http://ipm.ucanr.edu/PMG/PESTNOTES/pn74143.html) that is being watched, but is apparently not a danger to the local indigenous species. This was a strong contender when I looked up some images, but think it may be too small for my visitor.
Letter 3 – Drowned Tarantula
Spider with 10 legs???
I found this spider floating dead in my pool today. I fished it out, spread the legs out (which seemed to have small hooks on the ends), and took these photos. We do have a lot of Wolf Spiders here but this one seemed too big to be a wolf spider. Is it a Trap-Door Spider or a Tarantula? Do these normally live outside or are they found inside houses too. I would hate to wake up and find one in my bed. Plus are those "extra legs" in front the mandibles of the spider? And do they bite? Thanks for answering all my questions. Thanks for such a wonderful website,
Walnut Creek, CA
This is a Tarantula. During the winter in the American Southwest, male Mygalomorphs, the suborder that included Tarantulas and Trapdoor Spiders, wander in search of mates. There are many casualities, like your poor drowned suitor. Tarantulas might wander into homes, but they are just occasional visitors, not inhabitants. The fifth pair of legs you mention are called pedipalps. Pedipalps are enlarged in many male spiders so they can transfer sperm to the female.
Letter 4 – Faceoff between Desert Blond Tarantula and Arizona Bark Scorpion
July 17, 2010
Location: Cornville, AZ
Returning from our nightly walk our pug stopped dead in his tracks a few feet from our front door and wouldn’t move. This tarantula was the reason why. Upon closer inspection, we saw why he was there. He had a scorpion cornered by the wall next to the door.
Thanks so much for submitting your witness account of what might have become a food chain battle that would probably have interested many of our readers. You didn’t indicate how long the stand off lasted or if there was any human intervention. We believe your Tarantula is a Desert Blond Tarantula, Aphonopelma chalcodes, which is pictured on BugGuide. We believe the Scorpion might be the Arizona Bark Scorpion, also pictured on BugGuide.
It couldn’t have been very long – it was a short walk and they weren’t there when we went out. The area was in semi-darkness, the only light coming from inside the house – the front screen door. We turned around and went in through the garage. Unfortunately, my husband was not comfortable leaving the tarantula there so caught it in a glass and moved it back to the yard. It was only after that that I took a flashlight and inspected the area and saw the scorpion under a slight overhang against the wall by the door. Black widow spiders usually hang out there. This was the first time in our 5 years here we’ve seen a scorpion or tarantula in our yard, oddly enough, the first ‘critter’ we encountered here in the desert was a toad.
Thanks for your identification.
Letter 5 – Immature Tarantulas relocated in Arizona
Subject: Ugly spiders
Geographic location of the bug: Arizona
Time: 02:13 AM EDT
Your letter to the bugman: Hello,
I’m NOT a fan of spiders in my home, & we’ve seen Huntsmen Spiders here about 6″ crawling on the ceiling @ night-freaked me out!! I do have a healthy fascination for the tarantulas because they don’t come into my home!lol
While cleaning up debris outdoors at our new home we discovered 3 of the UGLIEST spiders, & after closer examination, we realized we uncovered baby tarantulas that grow to be absolutely stunning!! We felt badly as it’s now the cold winter so I felt badly as many species of tarantulas are in a rapid decline due to habitat loss & the pet trade, & we were able to find them a new home, however, we discovered that people who have lived here their entire lives have NEVER seen spiderlings, so here they are!
Desert Blondie (Aphonopelma Chalcodes)
How you want your letter signed: Sheila
Our first inclination was that your images picture Trapdoor Spiders, which are classified with Tarantulas in the infraorder Mygalomorphae, but upon thoroughly reading what you wrote, and then researching on BugGuide, we agree that these are immature Tarantulas. Thanks so much for sending in your images, and because, despite your dislike for Spiders, you took the trouble to relocate these immature Tarantulas, we are tagging this posting with the Bug Humanitarian Award.
I LOVE Tarantulas, & unfortunately, sadly they’re in decline all over the world, much of it due to pet trade! They are truly peaceful creatures and a threat to no one!
Thanks so much for honoring me with that reward, I feel very humbled seeing that many others do the same, although most everyone that looked at the pics “felt the hair stand up all over”! lol
Keep up the good work as you definitely have people look at bugs differently & in a positive way than they might have previously!
We are presuming you meant “pet trade” and not “pest trade” so we are making a correction.
Letter 6 – Male, not Female Tarantula, we believe
Subject: Tarantula gender (?)
Location: Southern AZ (Santa Cruz county)
August 21, 2017 8:36 am
Is there an easy way to determine the gender of our local tarantula without disturbing it? (photo attached)
Signature: Len Nowak (SALERO RANCH)
This looks to us to be a male Tarantula, and it looks remarkably like this Tarantula from Nevada we posted recently. We believe your Tarantula is a male for the following reasons. It has large pedipalps. The abdomen is small and the legs are long. Male Tarantulas tend to wander in search of a mate. Female Tarantulas are more sedentary, living in the same burrow for up to 25 years. We have not read that. We just believe it.
Letter 7 – Possibly Common Baboon Spider from South Africa
Subject: Spider in Cape Town
Location: Cape Town, South Africa
November 9, 2014 1:55 pm
We found this next to our home in Cape Town near table mountain – can you identify it?
We believe this is a Trapdoor Spider, a primitive group classified along with Tarantulas in the infraorder Mygalomorphae. We believe it might be a Common Baboon Spider, Harpactira atra, which we found on iSpot.
Letter 8 – Crevice Weaver Spider
Larger black and brown spider maybe tarantula
Thu, Jan 29, 2009 at 7:50 PM
We live in Dayton Nevada 15 miles from Carson City Nevada. My husband found this spider about 2 weeks ago underneath a board outside. In the last 2 weeks he/she has doubled in size and loves crickets. When we first found him/her was half the size it is now ( body is about 1 inch long and with the legs about an inch and 1/2 long. When we first found him/her it was all black now the rear end of the spider is a silky brown very short hair on the rear end and two back legs, upper part of the body is slick looking as well as the front two sets of legs. It appears that there is a set of eyes in the middle of the head, almost in a prymaid looking area. The spider has very larger feeder arms on the front as well.
The spider really doesn’t make webs, it seems that it only webs so that it can’t eat whatever it has bitten. So is this a baby tarantula? Thanks for your help.
All of your photos are quite blurry, but we believe this may be a young Tarantula in the genus Aphonopelma since the markings match some images posted to BugGuide. We will contact Eric Eaton to see if he is more certain. Is this spider now being kept in captivity? Are you, by chance, related to our good friend John who is a landscape architect in Laguna?
Fri, 30 Jan 2009 08:20:17 -0800 (PST)
You aren’t kidding about “blurry.” LOL! Impossible to be certain, but I think that the spider is a “crevice weaver” in the family Filistatidae. They should stop feeding the thing for awhile, too. Spiders are opportunistic predators, and will overeat if fed too regularly (in the wild they don’t know when the next meal is coming).
There are some great images of filistatids over at Bugguide that they can compare to. I’m pretty certain this is not a tarantula.
Here is an after thought, I was researching on bug guide and I believe now that this is either a trapdoor spider or a Crevice Weavers (Filistatidae) »Kukulcania I can not tell which. After looking through the pictures and looking at my spider, I see that he has bands on his legs where they attach to the body. I would better describe the hair as velvet looking. I just can not decided which spider he is and if it is a he or a she. I have also noticed he has atleast 1 dimple on his butt, and no spinnerets. I am unsure if either of these spiders are supposed to be in my area.
Thanks for all your help.
Letter 9 – Rosehaired Tarantula: Possibly a Gynandromorph???
Subject: Bisected Hair Growth on Rosehaired Tarantula
Location: Philadelphia, PA
March 19, 2013 7:21 pm
I wasn’t going to submit this question on What’s That Bug, because the species isn’t in question. My What’s That Bug dilemma is about this specific individual. This rose haired tarantula is part of an education program collection at a small arthropod museum in Philadelphia, PA. Her hair is significantly longer on one side of her body than on the other. She seems to be split right down the center. Also, her carapace seems to have less rosy iridescence on the side with the shorter hair. I’m wondering why she’s like this and hope someone here can provide an answer. I already showed these two photos to Eric Eaton. He suggested I post them to some spider forums, which I’ve done. I can take additional photos if needed.
It is much too late in the morning for us to research this more thoroughly since we have a train to catch, but we will post the first thought that came to our minds. This lateral split is sometimes seen in insects where one side is male and the other female, and this lateral hermaphrodite is known as a gynandromorph. Here is an example of a Tiger Swallowtail gynandromorph from our archives. We aren’t certain if there is sexual dimorphism in the Rosehaired Tarantula, but some quick research might reveal if our suspicion is correct.
Letter 10 – Rubber Tarantula Moved when Nudged.
So will a rock” noted Facebook poster Kristy Day.
Subject: What’s this spider?
Geographic location of the bug: La Quinta, California
Time: 02:20 AM EDT
Saw this tonight around 830pm in the parking lot of our post office. About 2-3 inches, not hairy like a tarantula, but we first thought that’s what it was. Very docile. We thought it was dead and nudged it slightly. It’s legs moved, but it didn’t crawl away, even after we walked away. There were two others in the parking lot several feet away. About 72 degrees, the beginning of fall in the desert.
How you want your letter signed: L Young
Dear L Young,
We suspect that either you are a prankster, or that you are the victim of a prankster. There is something about this “Spider” that just does not look right to us. The lack of articulation in the legs and the odd pattern on the cephalothorax, combined with the poor quality of the images (vaguely reminiscent of blurry Bigfoot, Loch Ness Monster and UFO photographs) has caused us to speculate that this might be a rubber Tarantula, similar to the one pictured on Amazon or the one pictured on Alamy. Halloween has just passed and perhaps someone at your post office was playing a joke. This is not the first time we have had a request to identify a fake spider at this time of year. We might be wrong, so we gladly welcome anyone able to identify this “Spider”.
We took these photos at night at our local post office parking lot – it had yellow lighting, which is why the lighting was bad – and the photo was taken with my cellphone, which is why it wasn’t professional quality photography. I am sorry that you think I was pranking you – I can assure you that I was not. My husband took that photo with my phone because I was too afraid to get close to it. He nudged it with his foot and the legs moved, so I highly doubt that it was fake. I guess I will have to try somewhere else to get an identification. We live in the desert and this wouldn’t be the first time that someone had a hard time identifying a spider out here.
Sorry I wasted your time – and mine. I’ll have to keep searching.
We did not mean to offend you Laura, but we honestly do not believe this is a real spider. Should you happen to get a proper identification, possibly from your local Natural History Museum, we would gladly welcome that information. Furthermore, we will attempt to get a second opinion and we will respond to you again with anything we learn, including any significant comments people make to the posting on our site.
A Facebook Comment:
It does look pretty plastic-y… (plasticky?) Like plastic. ~Tif
Another Facebook Comment from Mercedes
Behold the passive agressive plastic spider!
Kristy Day from Facebook Commented:
So she’s to sacred to get close enough to actually look, but it moved when it was kicked. Gee, I know a rock will move when kicked too. There’s no pleasing some people.
Ed. Note: Kristy’s comment really made us laugh. We wish we could let her know directly, but our editorial staff does not deal with the Facebook interface of our site, though we will copy and paste from it and we enjoy being shared.
More from Facebook:
Jen Smith commented “Hahah a day ago last year you guys posted a fake cockroach someone asked about 😉 (time line showed, Id re posted)“
Eric Eaton, author of Kaufman Field Guide to Insects of North America wrote back regarding our query.
I just returned from the Entomological Society of America national meetings in Denver the other day. One person knew me from WTB. 🙂
author, Kaufman Field Guide to Insects of North America
Letter 11 – Spotted Orb Weaver and Tarantula from Costa Rica
This spider is from 8/13/07 on Hilton Head Island. I couldn’t find anything on your site or on bugguide that quite matches. I don’t know how much variation there is in spider markings. Maybe I just missed it. Also, I thought you might like my Red Kneed Tarantula from Costa Rica. Thanks a million.
Sorry for the delay but we have had a very busy week at work and are a bit under the weather with flu-like symptoms. Your unidentified spider is a Spotted Orb Weaver, Neoscona domiciliorum. BugGuide has some nice photos of this species. Your Red Kneed Tarantula is also a wonderful addition to our site.
Update: (03/12/2008) Tarantula ID
Spotted Orb Weaver and Red Kneed Tarantula from Costa Rica (03/02/2008) Spider. I noticed you didn’t ID the tarantula on this post. It’s Megaphobema sp., probably mesomelas. Here’s a link to a good photo: http://www.birdspiders.com/gallery/p.php/233 Definitely not a red knee, with where it’s from 🙂 Great site, by the way. I love checking it out!
Letter 12 – Tarantula
Tarantula pics for you all.
It’s the time here in the central coast of CA when these handsome guys wander out looking for mates and higher ground. Saw this 5″ monster crossing the road and brought him home for some photos. He was very calm and only “shot” hairs at me once. Dropped him off right where I found him the next day on my way to work. Thanks for all the helpful information you provide on your site!
Thanks for sending us your high quality Tarantula photograph. We believe it is Aphonopelma iodius, a species found widely in California, Nevada and Utah according to Sharon McKenzie’s posting on BugGuide which states: “one of their characteristics is that dark triangle on the carapace that surrounds the eye turret area.”
Tarantulas — edible! (sometimes too much sought-after)
While the tarantulas of the American Southwest have traditionally not been eaten, this is not the case in the Amazonian rain-forest and the teeming tourist towns of Cambodia. The super-huge Theraphosa (so-called ‘bird eating spiders’) of Venezuela have traditionally been on the menu. The spiders are teased out of their lairs with grass; speared; and roasted over flames to singe off those urticating hairs. Actually there’s an unfortunate precedent: tarantulas served at an exotic foods banquet at the Explorer’s Club in NYC were insufficiently cooked, and some diners went to the hospital with hairs in their esophagi. The small town of Skuon, Cambodia, is well known for fried tarantula. People [I suspect foreigners, mostly] have traveled to Skuon in particular to partake from the stacked piles of black, shrunken bodies balanced on the bamboo trays of street-hawkers. Many conservationists suspect that the tarantula population will not sustain this kind of enthusiasm. Best,
Letter 13 – Tarantula
Location: Sonoma , Ca.
January 28, 2014 8:37 pm
I live in Sonoma, Ca. in the Boyes Hot Springs area. I found this spider in my water meter volt. I would appreciate your help in identifying it. It’s @ 1- 3/4” long and dark brown in color, it had no web that I noticed. Thank you for your help.
Signature: Rigobert gutierrez
This sure looks like a Tarantula to us. The eye arrangement, which is an important criterion for the classification of spiders, looks similar to the eye arrangement of the Tarantula on the PHotos of Utah Spiders site.
Thank you so much for your help. Additionally, can you please tell me what I should feed it.
Hi again Rigo,
That is a cricket with the Tarantula in the photo, and crickets make splendid food for spiders. You can buy crickets at a pet store. About.com has some information that might be helpful to you.
Letter 14 – Tarantula
Subject: Big spider in Arizona
Location: Central Arizona
October 11, 2014 5:38 pm
Dear What’s That Bug?,
While backpacking in the Mazatzal Wilderness near Payson, Arizona I saw this amazing spider! I thought it was my first tarantula, but after looking up pictures of tarantulas, I’m not sure. It was in early October in the morning and it was walking across the path. I managed to take two pictures, but it was moving pretty fast for a spider, so they aren’t great.
This is definitely a Tarantula, and our best guess is that it is a Desert Blond Tarantula based on images posted to bugGuide.