Kind: captions
Language: en
[Music]
all right you right to grab the back end
uh well not not at the moment yeah not
yet
so you lock him in
the scratch from this species will knock
you
knock you down
could kill you or oh definitely yeah
okay
so i am back in australia and of course
i'm reminded that everything in this
country is trying to kill you
particularly snakes and spiders and here
at the australian reptile park they
actually milk snakes and spiders so they
can use their venom to make anti-venom
and save lives let's go see how they do
it
all right so come on in man this is
without a doubt the most dangerous room
in the country you're currently
surrounded floor-to-ceiling with
venomous snakes
and the only thing that keeps the snakes
in is
those little locks yeah just the little
locks in the thin glass
did a snake actually do that yeah yeah
so a kid was tapping on the glass i told
him not to his parents like nah it's all
good and i'm like don't tap on the glass
man the snake goes
kid ran out of the uh smelling of uh
crap so yeah
for real yeah oh yeah he went
and went screaming out the room
in australia we lose one to three people
per annum to snakebite
internationally estimates by the world
health organization is 120 000.
so not only do we have some of the best
antivirus products anywhere on the
planet but we have a federally funded
anti-venom program which means no matter
who you are you get anti-venom for free
so we'll probably play with a big
coastal taipan to start with yeah and uh
so why why are we starting big oh might
as well you tell me what i need to do
right here i'm just going to grab a
vault from behind you because obviously
we use only the most highly scientific
pieces of equipment here at the reptile
park got it it's our shot glass
beautiful and uh i might even get you to
hold that for me a second this is one of
our big boys
hopefully he's in a good mood
as you can see quite a large individual
wow
now what we're going to do
yeah is pin him
now wait wait wait give him up
there you go you hold that i'll take
that vial off okay
this feels absurd there we go as you can
see he's keen on the killing now snakes
aren't stupid he doesn't want to bite
the jar he wants to bite me fingers the
target
[Music]
there we go oh my goodness
that was a lot of venom delivered very
quickly yeah they're not mocking around
wow
now what we'll do is we'll actually give
his venom glaze a little bit of a
massage so what you would consider is
cheeks give them a little bit of a roll
see if we can get an extra drop or two
because every drop matters
now because my hand's starting to cramp
up
i'm going to put him away so i'll get
you guys to jump back for me
and this is the sketchy bit yeah when
you get him out you got the hook when
you're putting him back
it's just who's quicker
ready
your hands trembling a bit yeah yeah
every time
so how much venom do you actually need
to make anti-venom about 15 15 snakes to
make one vial of any of that
venom evolved from saliva and it's used
primarily for catching and digesting
prey
each species of snake has a different
venom tailored to the specific animals
they hunt
the venom was originally squirted into a
snake's mouth by the back teeth and to
this day almost two-thirds of all snakes
are rear fanged now why the rear tooth
you might ask well it's because the
venom gland itself is actually behind
the snake's eye so the shortest distance
for a duct is directly downwards to the
back end of the top jaw
in some species evolutionary pressures
caused the fangs to move closer and
closer to the front of the jaw improving
the snake's ability to catch and kill
prey
while the location of the fangs was
evolving so were the fangs themselves
they started off as smooth ordinary
teeth with venom flowing down the
outside but over time some snake
lineages evolved a groove in each fang
to channel the flow of venom in some
species the groove became deeper and
deeper eventually closing in to form a
hollow tube and now the teeth literally
inject venom into prey
but this is not the norm only
one-seventh of the world's snakes have
hollow fangs
but of course almost all the venomous
snakes in australia do have hollow fangs
so we set up this macro shot to take a
closer look this one's rolling that
one's rolling we're ready when you're uh
perfect all right everyone's ready
[Music]
wow
it's got like jets
jets of venom coming out has this guy
not been milked in a while or yeah it's
been a little while
[Music]
not only do we have some of the most
toxic snakes in the planet here uh we
also selectively breed them for the
production of anti-venom
they're bred to produce more venom than
their wild counterparts so some of our
coastal tyre pens are producing six
nearly seven times what their wild
counterpart would and that's just from
selective breeding you find your two
most psychotic ones you put them
together you hope for the best and the
absolute worst comes out
so uh
keeps you on your toes that sounds
horrendous so you're saying that these
are the most venomous snakes in the
world and then you have bred them to be
more venomous yeah they're super snakes
a scratch from any of these animals
could kill you and uh some of these
snakes giving four and a half 4.9 grams
of venom per bite which is just stupid
amounts we spoke to venom expert timothy
jackson who argued these snakes produce
more venom because they are regularly
milked unlike wild snakes
either way the snakes in this room
contain more venom than virtually any
others on earth we house the second the
third the fourth the fifth and about the
twelfth or thirteenth most toxic
depending on who you talk to
one bite from a king cobra contains
enough venom to kill thirteen thousand
mice and we know this because of a study
from 1979 that tested the venoms of 25
different species of snake on lab mice
from this we can estimate that the venom
from one king cobra bite could kill
around four humans
though to be precise we'd have to say
four human-sized rodents because
thankfully no one's tested these venoms
on humans
and by this measure the most venomous
snake in the world is the inland taipan
which conveniently lives in the middle
of australia a bite from the inland
taipan has enough venom to kill half a
million mice or more than a hundred
humans so yeah why not milk that one
next so the next one we're gonna step it
up another notch so this is the inland
taipan also known as the fierce snake
the most toxic land snake on the planet
these guys have the ability with one
drop of venom to knock over 100 adult
humans so stupidly toxic
so quite a lot smaller than the last
couple of animals we've used but makes
up for it in toxicity very very quick
and very naughty when he wants to be
but an absolutely gorgeous pattern
you can grab that bit for me mate yes
i'm gonna grab this vial from behind you
and as you can see he's very keen on the
killing
there we go that is extraordinary
the most venomous
snake in the world
[Music]
just incredible animals aren't there
that was quick yeah those ones make me
proper nervous i don't know about you
guys but can i see the hands
the moment i stopped doing that after a
milking is the day i quit
the concept of the most venomous snake
is complicated because snakes evolved
their venom specifically for potency
against their usual prey
in turn their prey evolved resistance to
their venom the honey badger for example
is almost completely immune to cobra
venom so the lethality of a bite depends
on the snake the animal that got bitten
and the amount of venom injected the
reason scientists test different venoms
on lab mice is to get an estimate of the
amount of antivenom that would be
required to neutralize a bite
snake venom is lethal to us because we
are closely related to snake's main prey
rodents rodents and primates split on
the evolutionary tree only 75 million
years ago so we share a lot of the same
biology from the structure of our cells
to the way our blood clots to how our
nerves send signals venoms typically
target very conserved molecular pathways
that exist across maybe all vertebrates
or maybe even the entire tree of life in
in some cases
there are four ways that snake venom can
kill you it can be neurotoxic damaging
to your nervous system and brain by
interfering with neurotransmitters the
signaling chemicals that go between
neurons it can be hemotoxic thinning out
your blood preventing wounds from
healing and causing internal bleeding it
does this by disturbing the delicate
machinery of the blood coagulation
system venom can also be cytotoxic
attacking cells leading to severe
blisters necrosis and cell death it can
also be myotoxic destroying muscles and
causing paralysis
the worst part is that snake venoms can
contain up to 200 compounds most venoms
contain a combination of neurotoxic
hemotoxic cytotoxic and myotoxic
proteins
this is what makes snake bites so
difficult to treat it's not just one
toxin you're trying to neutralize but
dozens all working together to try to
kill you
one more
good boy there we go
i've been at the park for 10 years this
year uh i've been running this facility
for
uh seven and a half eight have you ever
been bitten
um
yeah so uh
about three and a half years ago i got a
scratch
um
one finger got nicked that was 36 hours
in icu and eight of those are on a
recess bay
so very very serious and what was that
experience like that that was crappy as
it turns out i'm highly allergic to
antivenom which is not ideal i started
swelling up looking like the elephant
man so then they whack you with the
adrenaline to cancel out the anaphylaxis
and then they have to give you more
anti-venom more adrenaline more
antimatter more adrenaline and
thankfully you only needed the one but
it was like the best case scenario so we
didn't chew we didn't buy it but
literally just just a scratch so what is
anti-venom exactly and how was it
invented
in 1870 a british military doctor edward
nicholson was stationed in burma
and as he watched the local snake
handlers he noticed something strange
they would from time to time
deliberately get cobras to bite them in
what he considered a form of tattooing
nicholson reasoned that they were
intentionally exposing their bodies to
the venom to develop an immune response
he observed that the older snake
handlers were less affected by
accidental bites than the younger ones
so this dangerous practice seemed to be
paying off
20 years later in saigon a french
medical researcher named albert calmet
was vaccinating local residents against
smallpox when he became aware of the
threat posed by cobras he wondered if it
was possible to make a vaccine for
snakebites
back in paris he tried injecting rabbits
with a tiny amount of cobra venom
starting with just .03 milligrams but
each week he injected the rabbits again
slowly increasing the dose and after
eight months of this the rabbits were
receiving 35 milligrams of cobra venom
at a time that is 15 times the normal
lethal dose in rabbits but they were
still perfectly healthy the rabbit's
immune systems had developed antibodies
to neutralize the venom
so you can be vaccinated against snake
bites just as you can against disease
but who wants to be vaccinated against
all different types of snakes just in
case one bites you it would be better
calnet reasoned if you could administer
antibodies after a bite
so he drew blood from a venom resistant
rabbit and isolated the serum which
contains the antibodies and then he
injected it into another rabbit that had
never been exposed to venom
when he subsequently injected it with
twice the lethal dose of cobra venom the
rabbit was just fine
immunity had been transferred from one
rabbit to another
this was the first anti-venom or as the
frenchman khalnet called it antivenin
which is why my phone always makes that
auto correction
to this day anti-venoms are made in much
the same way
at the reptile park they collect and
freeze the venom it's sent off to be
diluted and injected into a donor animal
usually a horse
horses are used because of their size
after increasing the dose over a period
of months the horse builds up immunity
to the venom and then its blood is drawn
and the antibodies are isolated only the
plasma is taken the red blood cells are
returned to the horse
those horse antibodies are the
life-saving antivenom
anti-venom works for the same reason
venom works because of our shared
evolutionary history with other mammals
the antibodies produced by horses are
very similar to the ones produced by
humans so they bind to toxic compounds
and neutralize them even in our bodies
but this way of making anti-venom has
downsides collecting the venom is
dangerous many donor animals are
involved and some people are allergic to
antivenom
scientists are now exploring the
possibility of producing antivenom using
genetically modified bacteria
they would produce the specific
antibodies needed to neutralize each
toxin in a venom
but for now
this is the way anti-venom is made how's
your arm it's a bit sore the shoulder's
a bit tender
the work zach and others like him do
saves countless lives all around the
world if you're up here for fame and
fortune and oh look how tough i am
milking snakes you don't last long you
get chewed on and you go oh this is not
for me if you're up here because you
love the animals and this is an
opportunity to not only work with the
animals you love but to actively be a
part of saving lives like i'm not smart
enough to be a doctor i'll just put that
out there straight away but i can swing
a snake pretty good
hey milking snakes is a very hands-on
activity and so is learning with this
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