Fun Science: Animals
Professor Gizmo (Amazing Science Presentations) gives expert video advice on: How can fish breathe under water?; Why do birds sing?; How many kinds of insects are there? and more...
How can humans be animals?
Humans are animals. Some people don't like to have themselves called animals. But if you look at the larger scheme of things, we can take a look at the two main kinds of living things - plants and animals. Well, humans are certainly not plants, so they fit into the category of animals. And that's why people refer to us as being animals, because we have all the characteristics of a member of the animal kingdom, and very few of the characteristics of a member of the plant kingdom. There are more living things than just plants and animals. There are plants, animals, protists, fungus... these are all large groups of living things. We're in the animal kingdom, and we fit best with mammals. We have hair on our body, we give birth to living young, we nurse our young with milk, and these are all characteristics of mammals.
How can fish breathe under water?
They use snorkels! No, actually fish have an organ called a gill. The gill has the ability to extract the oxygen that is dissolved in water. Humans do not have gills, but we do have lungs. Our lungs actually extract the oxygen from the air. So it's just two organs that have the same end product in there function, but one works under water and the other doesn't.
Why do birds sing?
Birds sing for a multitude of reasons. Sometimes they sing to just let other birds know that they're there, sometimes they sing to attract other birds, sometimes they make their sounds to keep a certain territory registered as theirs: "Get out of my area, this is mine, move along". So birds will use their song to communicate all kinds of messages to other birds and other animals in the area that they're living.
Where do bugs go in the winter?
Where do bugs go in the winter? Some of them head to Florida. Actually, they do. Some bugs will migrate. They'll go all the way down to South America. Some bugs will actually die, and some bugs in the winter, they produce in their bodies enough of a material that's almost like an antifreeze, and they will go kind of dormant over the winter. And then in the spring they get warm again and they kind of just wake up and take off and go again. That's why sometimes you have flies in the house very early in the season. After a cold winter snap you'll have flies because they quickly revive again. They all hide in places. Basically they have good hiding places because we normally can't see them. They'll hide in, like if it's in a house they'll find any little crack or crevice to hide in. Outdoors they'll be sometimes underground, sometimes in cracks of trees. They'll be all over, any place that they can hide and find protection from other animals that may be eating them. And sometimes they hide in areas where if they can get down deep enough in the ground, they will go below the area that will freeze, and they will survive the winter under ground.
How many kinds of insects are there?
How many kinds of insects are there? There are lots of insects. There are millions and millions of insects and insects are animals that basically have an excel skeleton and have six legs and some of them have wings. Some of them do not have wings. Some of them are very large. Some of them are very small. Some of them are friends such as bees. They go pollenate plants. We wouldn't have half of the fruits and vegetables that we have without these and other insects that do pollenation. There's all kinds of animals, excuse me, insects that are basically enemies of ours. They'll cause disease. They'll cause death. They'll transmit disease. There are ticks. There are flies. There are mosquitos. All of these... they can be good in one instance and alot of times the insects are food for other animals. In many instances they can be very harmful and cause death to other plants, to other animals and even to ourself.
Why do cats always land on their feet?
Atually, cats don't always land on their feet but they have the ability to land of their feet easier than other animals. This is because their nervous system is set up so that when a cat is dropped or it falls from something, it can right itself in the air usually fast enough so that when it falls, it will fall on its feet. We don't have that ability. A lot of the animals don't have this ability, but cats seem to be very agile. I think it's their sense of balance in their ears that they sense things are out of shape and they will align their head and the rest of the body falls into place and drop on their feet unharmed.
Why do reptiles lie in the sun?
Reptiles are a cold-blooded animal, and that means that their body simply responds to the temperature of their surroundings. When reptiles are warm, they're more active, and when they're cold, they're slow and sluggish. Sometimes reptiles like a turtle, or a lizard or something, will crawl out and lay on a log, or on a rock or something. What they're doing is warming their bodies up by the sun, so that their bodies get up to a nice temperature where they can move around faster. This is why reptiles lie in the sun.
How do chameleons change color?
Chameleons will change color because underneath their skin there are different layers and these layers will respond to the environment. Sometimes they use these for a kind of a defense where they can blend in better with their environment, like camouflage. Some chameleons will actually go through their color change very quickly, and some of them will take a very long time, but it's pigments under the skin, where certain pigments are allowed to be displayed more than others and they can change their color to match the surroundings.
How do flying squirrels fly?
Do you know what? Flying squirrels don't even fly, they glide. They have long stretches of loose skin between their front legs and their rear legs. And when they jump out of a tree, they'll spread their arms out like this and the flap of their skin will catch the air and actually glide. So flying squirrels aren't actually flying; they don't flap, and they don't have wings. Their bodies can stretch the skin out so it catches the air and slows the fall, almost like a parachute.
Do cows really have four stomachs?
Cows do really have four stomachs. And, what cows do with their four stomachs is they will eat food, which is basically grass; and cellulose is pretty hard to digest, and this is the main component of grass. Their stomachs will go through different processes where they'll eat something and they'll put it in one stomach, and a while later they'll bring it back up, and actually from one stomach they'll bring it back up to their mouth and they'll chew it up again, and then go back down again. So it goes through these series of stomachs to help their digestive processes because of the toughness of grass to digest.
How does a firefly make light?
Fireflies actually use chemistry to make light. They have bioluminescent chemicals in their body and when fireflies are actually turning their lights on and off, they are going through a chemical process. The chemicals in the abdomen, the lower part of their body, mix together and form this light. There are other organisms that are bioluminescent besides fireflies, and so they all use a chemical process. When these chemicals mix together, instead of giving off heat, give off light.
Are bats really blind?
No, bats are not really blind. Most bats can see. There are some bats that are blind. Most people say they are blind because they will fly at night. And they fly at night and they can do so well at night because they have a kind of sonar system. They'll either make their own sound and listen for the reflection of the sound back in their ears, or they'll listen for the sounds that other animals make. Their ears are very large, and they can get the sound back and they can determine where things are based on that. So they can fly very well in the dark by using, basically, sonar.
What are "fossils"?
Fossils can be of a couple different varieties. Some fossils are organisms that have died and all of the living substance has been replaced by mineral. Sometimes fossils are things that have been buried under the ocean and then sediment has fallen on them and left an impression. But fossils are kind of like remnants, or like our view into the past of what these organisms look like, their size, and their shape.