0:04 Honeybees are adorable. They're fuzzy,
0:07 colorful, and make delicious honey. They
0:09 also coordinate attacks on bears and
0:11 other mammals for the greater good of
0:14 the colony. How did an animal so cute
0:16 become such a
0:18 badass? What are the secrets of the
0:21 honeybee stinger? And why did they die
0:24 after stinging? This is the science of
0:34 Hi, I'm Danielle Dufo and you're
0:37 watching Animal Logic. Honeybees have
0:39 one of the most hardcore defense
0:42 mechanisms on Earth. When they sting a
0:44 large animal, like a mammal, their
0:47 stingers get lodged in their fo's skin,
0:50 and the bee dies. This is common
0:53 knowledge, but it isn't common behavior.
0:56 Most venomous insects can easily inject
0:59 their venom without dying. Wasps, ants,
1:02 and even other bees sting and live to
1:05 fly another day. So, why are the cutest
1:08 insects the most dramatic ones? Why do
1:11 they need to die for the greater good?
1:13 And how can losing brave warriors
1:16 possibly benefit the colony? These are
1:19 surprisingly complicated questions. So,
1:21 let's dig in. The beasting is basically
1:24 a venom injecting harpoon. If you zoom
1:27 in, you'll see two barbed blades and a
1:29 stabilizing structure to hold them in
1:31 place. The blades are controlled by
1:33 muscles in the bee's abdomen and are
1:36 thrust one at a time in an alternating
1:38 pattern. As the blades dig into the
1:41 skin, the backward-facing barbs catch
1:43 into the fleshy parts, helping them dig
1:46 deeper and deeper. The stabilizing
1:48 structure is connected to the venom
1:51 reservoir and deposits it as the blades
1:53 penetrate the skin.
1:56 Okay, that's terrifying, but it's not
1:58 too different from other stingers or
2:01 even the probosus of a mosquito. It's a
2:03 knife connected to a stiff hose, kind of
2:06 like a bayonet. The only difference,
2:08 which is a huge difference, is the
2:12 backwards facing barbs. The barbs, much
2:13 like the barbs of the spines of a
2:15 cactus, are designed to make the
2:19 stabbing easy, but the removal almost
2:22 impossible. It's a bit counterintuitive,
2:24 but a barbed stinger goes in easier than
2:27 a smooth stinger. The barbs help
2:29 concentrate the force at the tip of the
2:32 spear. So, the tiny honeybee needs less
2:35 force to pierce the tough skin of a bear
2:38 or a human. But because there's always a
2:41 butt in nature, the barbs make it much
2:43 harder to remove the stinger. The bee
2:46 would need about 10 times more force to
2:49 take it out than it needed to put it in.
2:52 And quite simply, she ain't that strong.
2:54 So instead of getting stuck forever and
2:56 then quickly getting squashed by the
2:59 mammal, the bee flies away and the
3:02 stinger gets ripped out of its body. The
3:05 venom sack stays attached and continues
3:08 to pump venom after the bee has escaped.
3:11 This is called sting automy, and it's an
3:13 amazing way to inject the maximum amount
3:17 of venom and cause the maximum amount of
3:19 pain. The ripping off of the stinger
3:22 also releases alarm pherommones. So, at
3:24 the same time as the mammal is being
3:27 injected without juice, chemicals are in
3:30 the air to tell the other bees to do the
3:32 same. This is how you end up with one of
3:35 those classic my girl situations.
3:38 Unfortunately, it isn't a clean break.
3:40 Along with the venom sack, parts of the
3:43 abdomen, digestive system, and muscles
3:46 of the honeybee are ripped off, which
3:49 inevitably causes it to die. But
3:51 sometimes it takes up to 5 days for the
3:54 bee to finally pass away. And during
3:56 this time, they can still chase the
4:00 mammal or even bite it. Yep, bees can
4:03 bite. Apparently, we don't even know how
4:05 much it hurts. We don't even know for
4:08 sure if bees feel pain at all the way
4:10 that we understand it, but that's a
4:12 question for another episode. What we do
4:15 know is that bees are very motivated to
4:18 protect their colonies and will make the
4:20 mammals suffer for a couple of hours and
4:23 then be very itchy for a few more days.
4:26 The idea of max pain is to discourage
4:28 the mammal from ever getting close to
4:31 bees again. But this is unlikely to
4:34 happen because honey is undeniably
4:37 delicious. You've probably noticed that
4:39 I've been calling the bee's mortal enemy
4:41 a mammal. This is because these
4:43 gut-wrenching stings are only lethal
4:45 when they're on mammals or other large
4:49 animals with elastic flesh and skin. Our
4:51 inherent squishiness is what traps the
4:54 stinger in our skin. When bees fight
4:57 other insects with hard exoskeletons,
4:59 the stinger doesn't get stuck. That
5:02 means they can sting multiple times just
5:05 like wasps and ants. But still,
5:07 sacrificing themselves by tearing their
5:10 guts apart is a pretty extreme behavior.
5:13 Why would a honeybee choose to do this?
5:16 And how could this have evolved? Female
5:18 workers, which are the only members of
5:21 the colony who can sting, already don't
5:24 get to reproduce. Only their mom, the
5:27 queen bee, gets to reproduce. Their job
5:29 is to make sure their mom has as many
5:32 babies as possible. And if it means
5:34 dying to protect their mom and their
5:36 siblings, that's a sacrifice they
5:39 instinctively make. Colonies have
5:41 thousands of honeybees. Losing a few
5:44 workers to scare off an existential
5:46 threat is more than worth it. Speaking
5:48 of their mom, the queen bee has a
5:50 similar stinger structure to the worker
5:53 bees, except she uses it to lay her
5:56 eggs. Their ancestors used those hoses
5:59 exclusively for reproduction, but over
6:02 time some species adapted to also use
6:05 them as venomous hypodermic needles.
6:07 Queens also have a stinger, but it's
6:10 smaller, less barbed, and used mostly to
6:13 fight other queens. Honeybees are not
6:16 the only social insects that sacrifice
6:18 themselves for the horde. Camponotus
6:22 ants, also known as exploding ants, can
6:24 crack open their exoskeletons and
6:26 release sticky chemicals to immobilize
6:30 predators and rival ants. Globetermes
6:32 termites also do the same thing to fight
6:35 off ants. So really, it's not that
6:37 strange for insects to sacrifice
6:39 themselves. But some others are
6:42 perfectly happy stinging you over and
6:45 over again. This is the case with the
6:48 most annoying insect of the summer, the
6:51 yellow jacket wasp. Yellow jackets are
6:53 everywhere these days. They have found
6:56 in humans a really consistent source of
6:58 food. They love sugary foods to get
7:01 energy for themselves and protein heavy
7:03 snacks to bring back to the colony to
7:06 feed the larae. If you try to fight them
7:08 off, you'll get quickly stung and the
7:10 wasp will fly away to continue looking
7:13 for food elsewhere. They're the worst.
7:15 The reason they don't die is simply
7:18 because their stingers are smooth. This
7:20 means the stinger doesn't get stuck, so
7:23 it can be used multiple times. The
7:25 trade-off is that each sting injects
7:29 less venom compared to a honeybee sting.
7:31 So why did they go that way? There are
7:34 two major differences. First of all,
7:37 honeybee predators are usually very
7:40 large, like bears who try to destroy the
7:43 colony and eat all the honey. They don't
7:45 give a bother if the whole colony
7:48 collapses after that. So, the bees need
7:50 to send a very strong message and
7:52 provide the most painful sting they can
7:55 muster in their little body. Wasp
7:58 predators are usually smaller. Birds,
8:00 small mammals, and other insects might
8:02 try to break into the colony to eat the
8:05 nutritious larae. They get attacked a
8:08 lot, so being able to fight multiple
8:11 times is more valuable than causing a
8:14 lot of damage, but just once. But
8:17 secondly, and probably most importantly,
8:20 wasps hunt. Adult yellow jackets survive
8:23 mostly on a diet of sugar. But the larae
8:25 need a lot of protein and other
8:28 nutrients to grow and reach
8:30 metamorphosis. So the adults hunt small
8:33 insects and other invertebrates to bring
8:36 back to the colony to feed the babies.
8:39 The babies in return secrete a sugarrich
8:42 goop out of their mouth which the adults
8:43 happily drink
8:49 up. Yeah, cool. That's nice, I guess.
8:52 Disgusting, but nice. The babies pull
8:54 their own weight since they're just a
8:58 few days old. They will one day grow to
9:00 ruin our picnics and steal our food to
9:03 exchange it for sweet baby goop. So,
9:06 there you have it. The combination of
9:08 having to fight off massive predators
9:11 and inject huge amounts of venom,
9:12 combined with the fact that they're
9:14 vegan and don't need their stingers to
9:17 hunt has created the perfect conditions
9:19 for honeybees to develop singleuse
9:22 defense mechanisms. It makes sense and
9:24 it's pretty cool to see how evolution
9:27 solved this problem for the bees. If you
9:28 want to learn more about the amazing
9:31 world of bees, check out this episode we
9:34 made a couple of years ago. And if you
9:37 can support any bee protecting NOS's,
9:39 please do so. Bees play a super
9:41 important role in our
9:45 ecosystems. We really need them. [Music]
9:51 So, what should we talk about next?
9:53 Please let me know in the comments. And
9:55 don't forget to subscribe for new
9:57 episodes every week. Thanks for
