00:00Did you know that the spiders are one of the animals that most people are scared of?
00:12There are millions of people who have arachnophobia,
00:18meaning that when they see a spider they run away screaming.
00:23The majority of these arachnids of eight legs have six or eight eyes,
00:33and yet they have poor sight.
00:42Did you know that the silk that comes out of the spider's abdomen
00:46is much more resistant than steel wire of the same thickness?
00:51Well, it is, and it's a lot more elastic.
00:58Some say that if you were to use a spider's web with the thickness of a pencil,
01:04it could stop a plane in flight.
01:07That's incredible!
01:12Humans can use the spider's web for many different things,
01:17such as bulletproof jackets,
01:20threads of suture for stitching wounds,
01:24clothes,
01:26violin strings,
01:28or ropes used to hold a lot of weight,
01:32such as the one used by this mountaineer.
01:35Did you know that spiders use their webs to hunt as well as to travel?
01:48The spider's web is very sticky,
01:50and when an insect lands on it,
01:53it gets stuck and can't escape.
01:56And the spider then makes the most of it to eat it up!
02:03They also use their web to make cocoons for their eggs.
02:09And some to glide from one place to another with the help of the wind,
02:14just like Spider-Man!
02:19The truth is,
02:20spiders and the webs they make with their silk
02:23are one of the most fascinating facts we can learn from our nature.
02:28Don't you think?
02:29Fun Facts About Nature
02:34Which material created by nature is the most resistant?
02:41We could think that it's iron or steel,
02:45but it's not!
02:48According to some scientists,
02:50the most resistant material created by nature is...
02:55A spider's web!
02:57Which can be up to five times more resistant than steel,
03:02and it's also very elastic.
03:09Spiders use their web to capture prey and feed.
03:16But us humans also use it.
03:19We use spider's webs, for example,
03:21to make bullet-proof vests,
03:24suture threads to stitch up wounds,
03:28clothes,
03:30violin cords,
03:32or special ropes
03:34that handle many kilos,
03:36like this escalator.
03:39Today we are going to learn about the invertebrate animals.
03:49You'll know that the animals are divided into two big groups.
03:53The vertebrates that have an internal skeleton formed by bones,
03:57and the invertebrates that have no bones,
04:01and the invertebrates that have no bones.
04:03All the invertebrates are oviparous,
04:13and we classify them in six big groups.
04:17Sponges.
04:18Sponges.
04:19Jellyfish.
04:20Corals.
04:21Worms.
04:22Molluscs.
04:23Echinodonts.
04:24and and arthropods.
04:32The sponges are aquatic animals
04:47that are shark shaped and the body is full of pores.
04:52It is very easy to remember this group because many times we use them in the shower for personal hygiene.
04:59Yes, many of the sponges we use in the shower are invertebrate animals.
05:10The jellyfish are invertebrate animals that live in the ocean.
05:15Their bodies are gelatinous and have tentacles.
05:19The truth is that when they appear in the beach it is very annoying because their tentacles have small venomous stingers that produce very unpleasant bites.
05:32Corals are tiny marine animals that produce limestone residue which give rise to beautiful shapes.
05:46Do you know this animal?
05:49Exactly, it's a worm.
05:52Worms are soft and long invertebrate animals that move by dragging their body in the ground because they have no feet.
06:01They can be aquatic or terrestrial.
06:05There are some worms that can be harmful and that is why we must be careful with them.
06:10Can you see this snail?
06:19Well, snails form part of the mollus group.
06:22Mollus have a soft body with their legs and can also be aquatic or terrestrial.
06:28Thumb, like the snail, is clamped and mussels protect the body with shells.
06:34But there are other mollus that don't have a shell to protect themselves like slugs or octopuses.
06:42The echinoderms are exclusively aquatic animals.
06:53Their bodies have cocarous plates that form a shell.
06:56Some echinoderms are balloon-shaped and are covered in spikes that they use to defend themselves, like sea urchins.
07:08Others are star-shaped and are of course called starfish.
07:14The arthropods are the most abundant animals on the earth.
07:29Of every 100 animals that exist, 80 are arthropods.
07:34These invertebrate animals have the body covered by an external skeleton called a cuticle.
07:39The most common way to classify the arthropods is by the number of legs they have.
07:47This way, we can classify them in four big groups.
07:51Arthropods with six legs.
07:54In this group, insects like ants and flies are present.
07:58Arthropods with eight legs.
08:00Or for example, the arachnids like spiders and scorpions are.
08:03Arthropods with ten legs include the crustaceans like crabs and lobster.
08:11Arthropods with more than ten legs like the centipede, as you can see,
08:16has much more than a hundred legs and are called myriapods.
08:19What?
08:20What?
08:46The arthropods are invertebrates, meaning they don't have internal skeletons.
09:06They are a vast amount of them, including this dancing crab, these dragonflies, this
09:13caterpillar, or even all these tiny ants.
09:17The arthropods are very different from each other.
09:20Or do you think this butterfly and this shrimp have a similarity?
09:27Truth is, they don't look alike at all, but yet all arthropods have common characteristics.
09:34Arthropod is a Latin word which means atro, joints and podos, feet or legs.
09:41The main arthropod characteristic refers to what their name suggests.
09:45They all have jointed legs.
09:49Another fascinating characteristic that they all have in common is that their body is divided
09:54into segments.
09:56Many of which, though not all, are protected by an external skeleton which is used as a
10:01shield or a shell.
10:05Some arthropods' bodies do not grow at the same rate as their exoskeleton, therefore
10:10making them shed it for a bigger size, a process known as malting.
10:16Arthropods can be either terrestrial or aquatic.
10:20The terrestrials, such as this scorpion, breathe through their trachea, whereas the aquatic arthropods
10:26breathe through their gills.
10:30Arthropods eat everything, some are herbivores, such as this caterpillar, others carnivores,
10:36like this praying mantis, and others omnivores, like the wasps, which eat everything.
10:45Most arthropods have internal fertilization and are oviparous, meaning they lay eggs to reproduce.
10:54Larvas hatch from these eggs and then go through different stages before becoming an adult.
11:00The changes is called metamorphosis.
11:05As there are so many different types of arthropods, they are classified into four large groups,
11:11depending on the amount of legs they have.
11:15Arachnids have six legs, such as an ant, flies, or those really annoying nets.
11:23The arachnids have eight legs, such as spiders or scorpions.
11:30Crustaceans have ten legs, like this shrimp or this shy crab.
11:37And the arthropods have more than ten legs, and their bodies are elongated, like these caterpillars
11:45or these centipedes.
11:48Now we're going to remember the most important things.
11:54Arthropods are invertebrates, and their main characteristics are the jointed legs.
12:01Their bodies are divided into segments.
12:04And they leg eggs to reproduce, meaning they are oviparous.
12:08The terrestrial arthropods breathe through their tracheas, and the aquatic arthropods through
12:13their gills.
12:14And they can be either herbivores, carnivores, or omnivores.
12:19Lastly and very importantly, you must remember that the arthropods are classified in four groups,
12:26depending on the amount of legs they have, insects, six legs, arachnids, eight legs, crustaceans,
12:35ten legs, and myropods are those who have more than ten legs and have elongated bodies.
12:44Today we're going to meet animals with eight legs, and they're a little scary.
12:50Today we're going to meet...
12:52Arachnids!
12:54Same as insects, arachnids are invertebrates and belong to the arthropods.
13:06But don't get confused, arachnids are part of a different animal group than insects.
13:13While insects have six legs, arachnids have eight, like you can see in these images.
13:23Spiders, scorpions, and dust mites are part of the arachnid family, and share a number
13:32of characteristics that we need to know.
13:34They have four pairs of articulated legs, don't have antennae or wings, but do have a pair
13:43of clamps by their mouth, called chalocera, that they use to hold their prey.
13:48A fun fact about arachnids is that they can't chew, so they swallow their prey by sucking them
13:58in.
13:59The soft parts as if with a straw.
14:03They are carnivores, and spiders and scorpions feed from insects, other arachnids, and sometimes
14:12more reptiles and mammals.
14:17An arachnid's body is divided in two parts, cephalothorax, consisting of the head and thorax,
14:25joined in a single segment, and the abdomen, that can be segmented or not.
14:33Scorpions breed through tracheas or pulmonary sacs.
14:37And when they're born, they look the same as they do when they're adults, but of course,
14:42they are much smaller.
14:48Scorpions and the biggest arachnids, the largest ones, can measure up to 20 centimeters.
14:55Scorpions, they have huge chalocera in their heads, and use them to grab their prey before
15:02they inject venom with their sting at the end of their tail.
15:13Spiders are the most popular arachnids, but also the scariest.
15:19Most of them are venomous, but very few are truly dangerous for human beings.
15:24The truth is, spiders are astonishing animals.
15:28Also, apart from being able to produce their famous spiderweb, they are able to hunt their
15:35prey in multiple ways.
15:38Look, look!
15:47Dust mites are the least popular arachnids, because they are so small, you can't see them
15:53at a glance.
15:54They are microscopic, but what is true is that they are everywhere.
16:00In every house, there are thousands and thousands of dust mites.
16:05Well, now we know a little more about arachnids, the truth is they're very strange and mysterious
16:12animals.
16:13But they're important for the balance of life, for this marvellous life.
16:20Goodbye friends, see you next time, and don't forget to subscribe to Happy Learning TV!
16:31The answer is surprising, because it depends on the type of ant it is and the work it does.
16:48Can ants live for a few weeks?
16:55Worker ants live for two to three years, and queen ants can live up to 15 years.
17:06That must be because they live like true queens.
17:16Can ants swim?
17:19Most ants can swim and are known to be very fond of water.
17:24In fact, some ants are able to live underwater, for two weeks, without going above water.
17:33Without coming up to breathe.
17:35How many eggs can a queen ant lay per day?
17:50Queen ants are the ones in charge of laying the eggs for the colony to grow.
17:57And the truth is, is that it grows very fast, because a queen ant can lay between 800 and
18:061,500 eggs a day.
18:10No wonder there are ants everywhere!
18:13What do ants eat?
18:19Ants are omnivorous animals.
18:23They feed on plants and the flesh of other animals.
18:26So, this means they have to hunt.
18:29And the soldier ants are in charge of doing so.
18:36Although they are very small, they are very organized and hunt in groups.
18:44They are capable of hunting animals much bigger than themselves, such as this worm.
18:57Do ants have brains?
18:59Yes, and very big ones.
19:03In fact, ants are the animals with the largest brains in proportion to their bodies.
19:09And they are also super strong, capable of lifting 50 times their own weight.
19:16To be equal to an ant, if I weighed 50 kilos, I would have to be able to lift 2,500 kilos.
19:31I can't even lift 100.
19:36It's a good thing they are so small, because if they were our size, it would be very scary,
