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Uploaded:2014-09-22
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Find out why these arachnids are among the least B of humanity’s BFFs. Yeah, they’re blood-sucking parasites, but that’s not all of it!

Hosted by: Michael Aranda
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Sources:
http://www.sciencedaily.com/releases/2014/02/140220102727.htm
http://www.vcahospitals.com/main/pet-health-information/article/animal-health/lyme-disease-in-dogs/837
http://www.cdc.gov/ticks/symptoms.html
http://www.stuffyoushouldknow.com/podcasts/why-ticks-suck/
http://www.tickinfo.com/
http://ngm.nationalgeographic.com/ngm/tellus/0010/tell_us4.html
http://animals.howstuffworks.com/arachnids/tick1.htm

[Intro]

Ticks suck! They feast on blood, they spread disease and they're generally just... the worst.

Ticks are members of the arachnid family, marked by their eight legs and lack of body segments. With over 850 different species, all with a vampire-like blood-lust, these ectoparasites make their living through hematophagy, or blood-sucking, on whatever mammal, bird, reptile or amphibian they can creep up on. 

Their bodies tend to be small and flat, sometimes no bigger than a sesame seed. They're stealthy, hardy, and have a vice-like grip on their hosts. Some species have even adapted to blend in with their host's bodies, including one that looks exactly like the scales of the komodo dragons that it feasts on.

But, you know, part of what makes these guys so sucky is also what makes them kind of interesting, namely that they have evolved a number of exquisitely ingenious tricks to get their blood-eating job done. For example, ticks can locate hosts by sensing their body heat, breath, body odors, moisture, or even vibrations. 

They'll position themselves on a well-used path, or in a burrow or den, and just hang out at the end of a blade of grass, waiting for someone to walk by, often with their front pair of legs outstretched like they're waiting for a hug.

It is a trick. It is not interested in hugging.

This is sometimes called questing, which is a pretty epic name for just sitting there, but when a deer, rabbit or toddler walks by, the tick just climbs aboard. Its eight legs are each covered in spiny little hairs, punctuated by a tiny claw at the end - all the better for grasping its host.

Once it's in position, a tick grabs the skin and slices into it before inserting its feeding tube. Some ticks excrete a cement-like goo that locks their mouth parts in place so that they can't fall off until they're done drinking. And their saliva also has a type of anti-coagulant in it that keeps the host's blood from clotting so they can keep sucking it up.

And if that wasn't enough, many tick mouth-parts contain fish hook-like barbs that point backward, making it harder to pull them out once they've started breakfast.

But aside from all that, an even better reason to dislike ticks is their tendency to spread to disease. If a host has a blood-borne infection, ticks will slurp up those pathogens with the blood and then transmit them to their next host through their saliva. And the list of diseases ticks can spread is long and scary, ranging from the now famous Lyme Disease to Colorado and Rocky Mountain Spotted Fever, Tularemia, Meningoencephalitis, African Tick Bite Fever, Tick Paralysis, and various other horrors.

Common symptoms of these ailments include fever, headache, rashes, swollen lymph nodes, fatigue and, if left untreated, possibly problems with the heart and nervous system and even temporary paralysis.

But perhaps the most bizarre and possibly permanent result of tick-bite is a severe allergy to red meat. Like, you'll be eating hamburger at a cookout, and all of the sudden it's anaphylactic shock, swollen tongue, shortness of breath, hives all over, and, "Oh god!"

So, if you live in the South Eastern United States, have been bitten by a tick or two, and can no longer enjoy beef, you can thank the Lone Star tick for your change in diet. This tick's saliva contains a sugar called alpha-gal that's found in certain types of meat, like beef, pork, and venison. Most mammals make this sugar, but we primates don't.

Now, normally we can eat those meats without harm, but when a Lone Star tick latches on to your skin, it injects a little of that sugar directly into your blood, which causes your immune system to create antibodies to fight the foreign sugar.

And that's all okay, until the next time you eat a Philly cheese steak, and your natural defenses start attacking that steak sugar as if it were an enemy invader.

It's the first known example of allergy transmitted through an animal bite, and the condition appears to be permanent...and untreatable. This allergy also appears to be specific to mammalian meat - so if you've been bitten, and still want to keep eating animals, poultry and fish are still fair game.

But, no matter what your eating habits are, keep a careful eye out for any kind of tick. You really don't want their hugs.

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