Tarantula Defense Mechanisms

A Note on Handling Tarantulas

Basic Care: What They Should Live In

Basic Care: What They Should Drink From

Basic Care: What They Should Eat

Range, Habitats, and Physical Attributes:
     Tarantulas are the largest spiders in the world and are found in almost all mild and tropical climates, from 40 degrees latitude (northern California) in the United States down to Chile in the Western Hemisphere, and China down to Australia in the Eastern Hemisphere.  Some live in warm tropical rainforests, and others live in desert highlands that may experience snow from time to time. They're generally hairy, come in an incredible variety of colors and sizes, and have enormous black fangs.  To grow, they molt out of their exoskeletons, a process that may take exhaustive hours of struggle (more on molting is here ).  Some arboreal tarantulas (such as members of the genera Avicularia and Poecilotheria) prefer to live in trees and on the sides of buildings.  Others, such as the King Baboons (Citharischius crawshayi), spend their time in self-constructed burrows.  There are tarantulas that can cross streams, some with no eyes, and some that make a hissing sound by "stridulating" or rubbing their body parts.  Beyond their obvious similarities of eight legs, fangs, and fuzziness, different species and even different individuals of the same species are, well, different- just like people, cats, and dogs.
 

Defense Mechanisms:
     The primary defense of ALL the tarantulas I have observed is running and hiding.  Second to that, some tarantulas from the Americas (New World) defend themselves by flicking tiny, irritating bristles (urticating hairs)  more often than they will defend themselves via biting.  Prescription-strength  cortisone or a shower with alternating hot and cold water can soothe the itching caused by urticating hairs.   The uritcating hairs can cause one to itch for a few hours or, in a sensitive individual such as myself, cause a rash and irritation for a few days.  Definitely DO NOT rub your eyes after handling a New World tarantula, as the urticating hairs can damage the cornea (Note: do not pick your nose after handling a New World tarantula.  You shouldn't pick your nose anyway).  Most "Old World" tarantulas (tarantulas from Asia and Africa) will rear up on their hind legs in an attempt to frighten a harasser if running and hiding don't work (keep in mind that there's only so many places to run and hide when you live in an aquarium). Most Old World species are usually quick to bite if warning doesn't ward off a potential threat like your hand.  Overall, I have NEVER seen a tarantula that was truly "aggressive" in the sense that it would attack unprovoked.  Those I deem "aggressive" on this site are ones that are just more prone to defending themselves.
     Almost all spiders possess venom, but few tarantulas have venom of significant consequence to humans.  The general reaction to their bites is some physical damage from the fangs piercing the skin (which is no big deal from a small spider, but a bite from a Theraphosa blondi with half-inch fangs may be something like poking a sharpened fork in your hand) and perhaps aching or cramping, some swelling, and local redness.  However, it may be possible that an individual could be more sensitive to tarantula venom than others given the situation and the individual's health. Also, some varieties such as Pterinochilus sp.  or those of the subfamilies Stromatopelminae and Selenocosmiinae have venom that may cause adverse swelling and irritation, much like a wasp's sting, or even more severe consequences like vomiting.  The Ornamental spiders of India and Sri Lanka (Poecilotheria) are suspected of having venom that may cause detrimental reactions ranging from respiratory discomfort to muscle cramps.   NOTE:  I used the words "suspected" and "rumored"; very little is known and even less is scientifically documented about  tarantula bites.   There is no telling how much venom test subjects injected, if any was injected at all (it is up to the spider whether or not to use its venom, and it may control how much it uses).  Studies with careful controls will have to be done to make an acceptable determination regarding certain species, but it can be safely said that most tarantulas can't hurt a healthy, semi-intelligent adult any more than a wasp or a cat could.  Consider this:  With as many tarantulas as there are in our homes and in the wild, I have yet to hear a reliable report of a single human death caused by one, and reports of more than minor reactions to bites are very few and far between. . .in fact, just getting bitten is not a common occurence at all.
     Most tarantulas will warn before biting in defense by rearing up on their hind legs and baring their fangs, but this may not be true of some arboreals.  Venom is not always injected when biting (it's up to the spider when and how much venom they use) and I've observed several species give slapping "warnings"  with their forelegs instead of immediately gouging their fangs in for all they're worth.  Based on my observations, two things are apparent:  (1) Tarantulas would prefer to avoid negative confrontations.  (2) Tarantulas can diffrentiate a hand from prey.
         The best advice for avoiding a "spat" with a tarantula is use common sense: If it seems like it wants to be left alone, leave it alone.  If it's a known defensive/high strung species, don't get experimental and taunt it like a jackass.  If it's normally docile, expect it to have its bad days just like you do (yes, they do have "moods", or at least behavioral reactions to a wide range of stimuli).

A NOTE ON HANDLING: Regard your tarantula like pet fish.  Neither are into being handled.  There are some species that put up with it (usually New World varieties) and others that will have a fit if you touch them (said fits include running around in a panic like a maniac while pausing to flick hair and/or rearing up to bite).  Check the general "species info"  page on this site and learn about a tarantula's origins and potential temperament (remember that they do have individual personalities, though).  Also, browse further on the internet to find out what kinds you can pick up without the imminent risk of them flying out of your hand to a free-fall death and/or biting you.  Do both before "trying out" a spider.  Above all, remember that just because your redknee will sit still in your hand does not mean it's thrilled about the whole affair.  Give them plenty of solitary, personal time, be slow and gentle if you want to pick them up, and NEVER use your bug as a "party trick" in which you scare people with it, pass it from person to person, etc.  Such things are not only stupid and cruel- they're a green light for harm to you, your guests, and the spider- emotionally and physically. You may think it's funny to see your arachnophobic San Francisco DUI lawyer get passed your tarantula, but not only could it harm the spider it may cause legal problems if he ends up getting bit.
 

WHAT SHOULD THEY LIVE IN?
 

Again, a pet tarantula is best regarded like a pet fish.  You want to provide a secure living environment for your fish, as it would die if it got out.  Same for your tarantula.  Your home may be cozy to you, but it's a jungle of deadly hazards to a spider.  There is probably pesticide and cleaning product residue in your house, perhaps there's a violently curious cat, and there are all sorts of things that a delicate tarantula could fall off of or be squashed by (like your butt when you sit down on an unsuspecting spider that's hiding in a couch cushion).  In short, make sure they can't get out of what you put them in.
     Fortunately, living quarters for a spider are cheaply and easily acquired.  Spiderlings do well in deli cups with ventilation holes poked in them (poke the holes in the cups, not the bugs).  For larger tarantulas, any container that can be ventilated and made to have a securable opening for you to go in and clean, change the water, remove the spider, etc. will do.  Glass aquariums go well with lids (be cautious of most pre-made screen lids for reptiles.  Tarantulas can get their claws caught in those), plastic shoeboxes and their counterparts do fine if you ventilate them, and large, clear candy containers with screw on lids (like you may see full of jawbreakers on the counter at convenience stores) work.
    Give your bug some dirt (substrate).  Peat, potting soil THAT DOES NOT HAVE PESTICIDES OR PLANT FOOD OR FERTILIZER IN IT, vermiculite, etc. make for a happy bug.  A lot of people seem to use a peat/vermiculite mix.  I use a lot of peat and plain topsoil, and sometimes some vermiculite.  Don't put things like cedar shavings in there (that might irritate your spider); wood chips and the like are for hamsters, not spiders.  In fact, anything you find for sale at a pet store is probably a poor choice for tarantula substrate.  Bark chips and gravel are not very comfortable, and water will go right under sand to make a stagnant haven for all kinds of nasties.  Compressed ground coconut husk costs a lot more than peat moss. Be safe and save lots of money- use nice, normal "clean" dirt (there's an oxymoron for you) that you may find in a gardening or department store.  How much of this dirt you need depends on your tarantula.  If it's a burrowing species, give it enough to do plenty of tunnel making.  If it's non burrowing terrestrial, give it enough to make any modifications it may feel like making and provide some sort of shelter to hide in when it doesn't want to be bothered.  Those foam "coolies" that you might put a beer in make decent shelters, as do cork bark, small clay pots, little doghouses lovingly constructed from pizza box cardboard . . . anything that will provide a place to hide.  Plants may enhance the look of your spider's home and provide cozy hiding spaces.  Use fake plants if you desire greenery- the tarantulas won't notice the difference and it will save you a lot of trouble.
     If your tarantula is a ground dweller, provide enough room for them to wander about a bit, but don't make looking for food a major quest for your poor bug.  Though they do it well, it's probably a pain to catch a cricket with one's mouth, so don't make it too hard by putting a tiny tarantula in an immense enclosure with lots of decorations for prey to hide in.  My 5 1/2"  B. albopilosum seems pretty content with her 5-gallon enclosure.  If your tarantula's arboreal, make sure it has enough vertical space to climb around in.  They're not so concerned with horizontal space.  For clarification (or to further confuse you), enjoy my child-like drawings below:
 
  Note:  You may also choose to put the arboreal's water dish up high where it can be more easily accessed.      Another consideration for terrestrials is height. There is no need for them to climb, so go ahead and fill the substrate up until the depth of empty space at the top is about the height of the spider's legspan.  That way, they won't fall and get injured.
I've included more detailed notes on housing  with real pictures here.

Make sure your spider has clean water!  Spiders of decent size (about 2 1/2" in legspan), including the Cameroon Red will drink out of a water dish.  Some of my smaller ones use the caps from "widemouth" Gatorade jugs and others have plastic tops from peanut butter jars.  Anything that's shallow enough for your spider to stand over will work, and there's no need to stick a sponge or cotton in it.  In fact, making your spider drink from a wad of cotton or sponge is a bad thing because crickets will lay eggs in the moist sponge, cotton will get caught on your spider's fangs, and both get stinky and dirty.   Spiderlings will drink water droplets from light mistings (I use a thoroughly cleaned out spray bottle for that).   I must stress that you use VERY light mistings with smaller spiders and NO water dish for the teeny tiny ones.  I put more information and pictures of water containers for tarantulas here .
     Some tarantulas like it dry and others need a good deal of humidity.  Figure out what your species needs and mist a lot, a little, or not at all as necessary.  No tarantulas live in mildewy bogs, so never make a moldy, smelly swampland out of your spider's home.  I once saw a beautiful wild-caught king baboon die in a pet store due to the fact that the owner read that "baboons like some humidity".  He put the spider in a frog's environment and the poor thing was huddled up in the only somewhat dry corner of a moldy aquarium.  They decided that was too much moisture and so put the beautiful 7-inch tarantula in a completely dry, sand-floored terrarium without a water dish.  After a bit, it curled its legs up under itself in a dying posture, so they misted the container profusely and made another fungus-laden swamp, but no water dish.  It died what must have been a miserable death.
 

Preferred Food:
     A tarantula will eat just about any insect it can overpower. Studies have shown that tarantulas and most spiders are most comfortable eating prey that is about 50-80% of their body length, but of course they will take smaller and, on occasion, even larger prey if hungry (Netwig and Wissel 1).  They have also been known to devour mice, frogs, snakes, each other, and even fish!  Some will gorge themselves on as many prey items as they can and others will stick to an apparent "diet."  Sometimes they fast for long periods for unknown reasons and they almost always avoid eating when they're about to molt.

    Don't feed your spider anything that may have poison on or in it!    Most could do quite well on a diet of crickets alone, but you can try roaches, little lizards, superworms, newborn mice. . . just about anything small and defenseless.  In fact, studies have shown that spiders in the wild variate their diets and that they do indeed require a myriad of nutrients (Toft 304).  You can "gut load" crickets with different vegetables and other foods by letting the crickets enjoy a "last meal" the day before serving 'em up to your tarantula.  If you live in an urban or suburban area that sprays for pests or where lawns are chemically treated, do NOT just find a grasshopper or something outside and throw it in with your tarantula.   Remember, even if it's alive, the reason you were able to catch it is probably because it was in the process of dying and you could pass the same harmful chemicals on to your beloved pet.  Also, older mice, larger lizards, etc., may be able to bite your tarantula.  Leave such things out of its diet.
      When your spider eats, it will snatch up the food with its fangs and mush it around with its pedipalps , sort of like a baseball player chewing tobacco.  Unlike some other spiders, tarantulas don't just make a neat little hole and suck the juices out of something- they have to masticate and let their digestive juices run all over their prey, then suck.   Also like a tobacco chewer, it will leave a wad of gooey leftovers when it's done.  Remove those and any prey not eaten within 24 hours, for the wads of former crickets and stuff will make your spider's home unsanitary and may attract disease and mites, and uneaten things will pester your tarantula.
     Some people have tarantulas that eat pre-killed prey like slices of beef heart, frozen and then thawed pinkie mice, etc.  I tried chicken livers once and found, that while some large spiders enjoyed it, the smell was not worth it.  In addition, I have had tiny A. avicularia (pinktoe) spiderlings eat pre-killed crickets when they would not accept them alive.
      There is more information on tarantula food here .
 
 

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apolysis- another word for molting or ecdysis; when a spider sheds its exoskeleton

arachnid-  arthropods with four pairs of legs and one pair of pedipalps (sometimes in the form of claws).  Scorpions are arachnids.  So are tarantulas and garden spiders.

araneae- an order of arachnids commonly called "spiders".  Black widows are a member of this order and so are tarantulas. Scorpions are not.

arboreal- Lives in off the ground, like in trees

arthropods- bugs like insects, spiders, centipedes. . . the whole lot of 'em

book lungs- Little flaps on the underside of  a tarantula's opisthosoma (abdomen) that it breathes with.  There are four.

carapace- This is the top half of the cephalothorax and is hardened, yet often has a thin mat of fur.  The eyes protrude from the top of the carapace.

cephalothorax- This is the forward section of a tarantula that all the legs come out of.  It's akin to both the head and thorax on insects, all in one neat package.  It has the eyes (all eight of 'em), the chelicerae and fangs, and the tarantula's brain is inside.  Also called the "prosoma."

chelicerae- extensions that come out of the cephalothorax .  They contain hinges upon which the fangs move; i.e., the "top part of the fangs".  They are the "basal" segment of the mandible.

CITES- Convention on International Trade in Endangered Species.  Tarantulas from the genus Brachypelma are on CITES.

coxa-  Where a tarantula's legs attach to its cehpalothorax


ecdysis- when a tarantula sheds its exoskeleton in order to grow

epigastric furrow-  A slit betwixt the two forward book lungs that contains a tarantula's reproductive mechanisms

femur- The long leg segment close to a tarantula's body, like your femur

fovea, or thoracic fovea- An indentation in the carapace of a tarantula

hybrid- the offspring of two different species.

instar-A period between molts in a tarantula's life.  A tarantula in its 5th instar has shed its "skin" five times.


keystone species- An animal that is crucial to its niche, or habitat.  Some tarantulas are keystone species due to their diets.


mandible- consists of chelicerae and fangs

metatarsus- the leg segment between the tibia and the tarsus.  There is no metatarsus on the pedipalps.

molt- the same as ecdysis: when a tarantula sheds its exoskeleton in order to grow.  They usually lie on their backs to do this.

mygalomorphae- an infraorder of spiders with fangs that move on a horizontal plane (straight up and down).  Tarantulas are a type of mygalomorph.  So are trapdoor spiders.

new world- Tarantulas from the Americas

ocular tubercle- The raised section on the carapace that has clear little domes that a tarantula's eyes can see through

old world- Tarantulas from Asia, Africa, and Europe.

opisthosoma- The "rearward" section of the tarantula that contains the spinnerets, the book lungs, the epigastric furrow, and the anus.  The heart is also inside the opisthsoma, so be careful! In the case of most New World species, the opisthosoma has urticating hair.  Also called the "abdomen".

opportunistic burrower-  A tarantula that seeks a provided shelter instead of constructing its own from scratch.

oviparous- egg-laying.  All tarantulas are oviparous- that is, they do not give birth to feeding, breathing young.

patella- the leg segment between the femur and tibia (you may think of it as a spider's "knee").

pedicel- small tube that connects the opisthosoma to the prosoma.

pedipalp- Like a tarantula's "arms."  Located on the sides of the chelicera and used to grasp prey, serve as "feelers," etc., they look like smaller, extra legs.  However, the pedipalps only have six segments (legs have seven).  Males put sperm in the ends of their pedipalps to mate with.  Scorpions have claws for pedipalps.

plumose- Literally, "feathery."  Used to describe some of a tarantula's "hair."

prosoma- The "front" section of the tarantula that contains the carapace, eyes, fangs, etc.

rastellum- spines  that overhang the mandible.  Most mygalomorphs have these.  Tarantulas do not.

scopula- Dense hairs of uniform length on a tarantula's "feet"

sigilla- indentations on a spider's sternum.

species- a natural population that can breed and produce fertile offspring.

spinnerets- Appendages on the rear of a tarantulas that are used to spin webbing.

spiderling or s'ling-  Baby tarantula

stridulate- when a tarantula makes a hissing sound by rubbing specialized hairs on their chelcerae and pedipalps.  It means the spider is upset.

substrate- the substance placed on the floor of a terrarium.  Usually dirt, peat moss, sand, vermiculite, etc.

tarsus- the last leg segment; the equivalent of the foot.

taxonomy- the study of the relationship of different species

terrestrial- A tarantula that lives on or in the ground, as opposed to arboreal ones that live in trees and on the sides of other structures.

theraphosidae- A family of mygalomorphs commonly called "tarantulas."  Actually, a true tarantula is not even a mygalomorph (it's a European wolf spider called Lycosa tarantula) , but the word "tarantula" has come to be more commonly associated with theraphosids, especially in the United States.

tibia-  A leg segment away from the tarantula's body, after its "knee," like your tibia.  Most mature male tarantulas have a small hook under each tibia.

tibial spurs- hooks on most male tarantulas' tibias that are used to secure a female's fangs while mating

trochanter- the leg segment between the coxa and the femur.

urticating bristle or hair-  Teeny tiny barbed hairs on most New World tarantulas' opisthosomas (abdomens) that they can flick off by rubbing their hind legs rapidly against their rears.  The result is a an almost unseeable cloud that floats off into the air (with the exception of tarantulas in the genus Avicularia) and will cause potential threats (such as rodents and people) much irritation.

ventral- the underside of something. The ventral surface of a tarantula is its "belly."

 

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