What animals are considered mammals? – Mammals 4 Kids

Mammals (Latin: Mammalia) include humans and all other animals that feed their young with milk. Most mammals are covered with fur and have specialized teeth that help them cut or chew food. Compared to other vertebrates (vertebrates have backbones), mammals have a more well-developed brain than other types of animals. Besides humans, mammals include some of the most famous members of the animal kingdom, such as cats, dogs, elephants, and whales.
Mammals breastfeed their young and this is their main feature. Mammalian young are born already formed. Before birth, the young develop in their mother's stomach. It feeds in the uterus via the placenta. The umbilical cord connects it to the placenta through which large blood vessels pass, brings food from the mother, and takes away the waste. The time it takes a young to grow up in a mother's body is called pregnancy and does not last equally for every mammal. When born, the young is a faithful image of his parents.

Do mammals have other characteristics?

So far, we have seen two: a young is born formed and sucks milk from his mother.
On top of that, most mammals, except for whales and dolphins, have skin covered with hair. The skin of bats, the only mammals that fly, is oily. Mammals have important glands, such as sweat, saliva, etc.
Mammals also excel at constant body temperature. They are called "warm-blooded." The temperature ranges from about 35° C to 39° C (for rabbits and cattle).

Other important features: 

• They need air and breathe (the mammals that live in the water from time to time come to the surface to take in the air). 
• Their central nervous system has been developed. 
• They have venous and arterial blood.

How are mammals different from other animals?

Mammals are warm-blooded. It is thanks to the heart. Blood helps to regulate heat. The mammalian heart consists of two atria and two chambers, completely separate. In most mammals, the brain is well developed. That's why we come across highly intelligent species, such as anthropoid apes and dolphins.

Mammals are also characterized by the specificity of their food-dependent teeth. Some change their teeth only once, in others their teeth grow without interruption.
All mammals have joints by which one or more bones bind to each other, creating one movable whole. The bones are firm and hard, which is why there can be very large animals. Many mammals have seven vertebrae each, which forms the spinal column. Sloths (family of South American mammals) and sea cows make an exception because they have more. Reptiles and birds have many more.

Where do mammals live?

Mammals exist in all parts of the world. Areas, where only certain species of mammals live, can't be accurately identified.
Most of mammals live on dry land, but others like moles and some kind of mice live in the ground. Representatives of individual ranks live in the water and they come to the ground to fetch the cubs or rest, but seek their food in the water. Whales don’t go on land since this would mean death for them and their young are born in water.
Other mammals like bats, for example, can fly.
Flying marsupials  (flying squirrels, for example) have flying skin between the front and rear limbs thus can glide from one tree to another.
Once upon a time, lions and bears lived in Europe, and the tiger is not exactly a tropical animal. It could also be found in the north of the European part of Russia. Studying the habitat zones, we see that only the biggest obstacles prevented mammals from spreading everywhere. These are high mountains (like the Himalayas), oceans, deserts (like the Sahara) and climate.

How do mammals adapt to their environment?

If we analyze their classification, we will notice that this group of animals is very different from one another according to their diet. Some eat meat and other grass for example.
Mammals who feed on insects have pointed teeth so they can pierce the insect's armor.
Carnivores must have pointed molars in order to tear their victim's flesh. In contrast, herbivores have molars adapted for grazing.

The hedgehog feeds on insects. With its muzzle, it looks for food under the leaves and moss. It gets out at night. Hedgehogs have spines instead of fur. In addition, their body is wrapped in a single circular muscle. If the hedgehog is threatened, this muscle shrinks and the animal becomes a spiny ball. Even the fox will escape. In winter, hedgehogs sleep in sheltered places. The heat of their body goes down several degrees above zero. If the weather gets colder, they wake up to keep the warmth.

Some have long sticky tongues that serve them to catch ants and termites.
Nutrition that determines lifestyle requires adjusting the teeth, legs, and senses.
The Asian tiger, African lion and leopard, and American puma have many similarities, as do the Asian buffalo, the European bison and the Cape buffalo in Africa. This is because animals eat the same type of food and tend to adopt the same way.
Mammals living in water adapt otherwise. Their body is aerodynamic, and the limbs have turned into fins that house the limb skeleton. They are clumsy on earth because water is the environment in which they live. The glands in their skin are very important because they maintain body heat. Those mammals that live underwater can close their nostrils.
Whales have nostrils on the upper side of the head.

The rabbit is a rodent with big ears and a small tail. Its anterior, upper and lower teeth are long and chiseled; they grow constantly because they are spent while rabbit feeds itself. Rabbits live in underground habitats. They go out at dusk to feed on roots and grass. They originate from the Mediterranean area and are very fertile.

We will understand better what adaptation is by studying the same animal species under different climatic conditions. If we analyze for example three types of foxes: in the North, we find a polar fox with small ears; the foxes in Europe have bigger ears and the desert fox has very big ears. Why this different size? This is one way to regulate body temperature.
It should be known that two species of the same family, which feed differently, they also adapt differently.
The white rhino has a long neck since it grazes the grass. The black rhino has a shorter neck since it eats leaves from the bushes.
There is another adjustment to the color and patterns of the fur. It's hard to spot a tiger in nature because of its striped fur. It is similar to deer moving in the forest. Cubs (smaller in size) often have different fur than adults. Wild pigs also have striped fur, and many more examples can be found.

How does a snake swallow an animal which is larger than its mouth?

The diameter of a snake's body does not usually exceed the size of a fist, but it can still swallow a large chicken or rabbit. The Southeast Indian or nettle python is one of the largest snakes in the world, it can swallow wild boar and even deer.

This is possible because the snake has very stretchy jaws, the shape of which is different from that of a human.

Our lower jaw joints with the upper one are at ear height. For snakes, there is one extra bone that connects the ends of the two jaws with a double hinge, allowing them to be very separated from each other. The snake swallows its victim whole, covered with hair, feathers, shells, horns and more. Before the snake swallows its victim, it kills it first, whether using poison or more often, clamps it with her body until she chokes it.

Because snakes teeth are bent backward, the snake must swallow the whole victim because it cannot chew or retrieve it.

Where do sea turtles lay their eggs?

As the egg-laying age approaches, the female turtle emerges from the water. It is difficult to navigate the coast looking for a safe place. Using her legs, which are used as fins in the water, she digs the ground to make a nest. In a few hours, the turtle will lay 100 to 150 eggs. Completely exhausted, there is so much power left to overwhelm them.

After the eggs hatch, the turtle slowly returns to the sea. After a while, small turtles are born, which themselves have to cross a dangerous path to the sea where they can be killed by predators.

What is a Backbone and What does the Backbone do?

Vertebrate animals have a spine, or backbone, and a cranium (brain case). 
The spine is a long column of bones called vertebrae that run all the way along an animal’s back.
Most vertebrates have vertebrae made of bones.
Some, like sharks, have vertebrae of cartilage.

We can feel our vertebrae by running our hand down the back of our neck and between our shoulder blades.
Can you feel a row of hard, bony lumps?
They run all the way down to your bottom.

Every animal in the six classes of vertebrates - bony fish, cartilaginous fish, amphibians, reptiles, birds and mammals - has a spine or backbone.

What does the backbone do?

The backbone has a very important job to do.
Every vertebra that makes up the backbone has a hole in the middle, and is joined to the next by a rubbery pad of cartilage.
The backbone is like a flexible, hollow tube. Through the middle of this tube runs the spinal cord.
The spinal cord is a thick bundle of nerves that carries messages from a vertebrate’s brain to the rest of its body.
The spinal cord also carries information back from the body to the brain. The backbone protects this vital passageway of nerves.

Every animal in the six classes of vertebrates:

• bony fish, 
• cartilaginous fish, 
• amphibians, 
• reptiles, 
• birds, and 
• mammals

has a spine, or backbone.

Messages travel rapidly along the nerves between your foot, spinal cord, and brain.
When the water is too hot, you quickly lift up your leg.
Your brain then receives a signal that the foot is now out of the water.
If you dip your foot into hot water, messages will race through your spinal cord and to your brain to say that the water is too hot and that it’s causing you pain.
Messages will then race back to your leg muscles to take your foot out of the water.

Imagine how busy the nerves in your backbone are! 
Thousands of messages rush along them every second.
If the spinal cord gets damaged, these messages can’t get through. Sometimes, people who have injured their back can’t move certain parts of their body.

Types of Mammals - What is a mammal and what do all mammals have in common?

The blue whale is the largest animal that ever lived. An adult blue whale can measure as long as 100 feet (30 meters).
It weighs about 190 tons.
An adult giraffe can grow to be about 18 feet (5 meters) tall.
An Indian bull elephant weighs nearly 4 tons.

What is a mammal?

You are a mammal. 
Cats and dogs, goats and horses, apes and monkeys, giraffes and elephants, even whales and dolphins are all mammals. 
There are about 4,000 different species of mammals. 

What do all mammals have in common?

Mammals, like other vertebrates, produce eggs. But most of them don't lay the eggs and wait for them to hatch. Instead, the mother keeps the eggs inside her body and the young grow inside her until they are ready to be born.
After birth, the mother feeds her young on milk she has produced herself.
Most mammals are covered with fur, hair, or bristles. Some mammals, such as elephants, have very little hair. Our ancestors had thick hair all over their bodies.
Today, human beings have thick hair on only some parts of their bodies.

Scientists can sort, or classify, mammals into smaller groups by looking at the ways they produce their young and care for them.

The different types of mammals, scientists have sorted into three groups:

• placentals,
• marsupials,
• monotremes.

Placental mammals

Humans, and most other mammals, belong to the placentals group. 
Before they are born, placental mammals develop inside the mother.
They are attached to their mother by a cord, or placenta, through which they get their food.
Newborn placentals are already well developed.
 Have you ever seen a newborn calf or foal? 
Most can stand after only a few minutes. Newborn whales can swim at once.
Human babies are still quite helpless.

Marsupials

Kangaroos, possums, wombats and koalas are marsupials. 
Most marsupials live in Australia. These mammals give birth to tiny young that don't look a bit like their parents.
These tiny creatures wiggle their way through their mother's fur and into a pouch below her stomach.
Here, they feed on milk until they are big enough to leave.
Whenever they are in danger, they return to the pouch.
A young wallaby stays in its mothers pouch for several months after its birth.
This fat-tailed swamp wallaby and her baby live in the east and south of Australia.
Wallabies are smaller members of the kangaroo family.

Monotreme mammals

The third group of mammals—the monotremes— all live in Australia or on islands nearby. 
There are only three species of monotremes—one species is the duck-billed platypus.
The other two are different species of spiny anteaters.
Monotreme mammals are classed as mammals because the mothers produce milk. 
But their young aren't born like other mammals.
They hatch out of eggs.

What do mammals eat?

Most mammals have some sharp teeth at the front, called incisors, and some blunter, more rounded teeth at the sides, called molars.
Some mammals also have sharp, pointed teeth called canines.
You can tell what kind of food a mammal eats by looking at the shape and position of its teeth.
It will eat either plants, or the flesh of other animals, or both.
A few mammals eat only insects. They have unusual teeth or none at all.
Mammals can be grouped, or classified, by the kind of food they eat.
The kind of food is related to the kind and placement of the teeth.

Plant eaters

Most mammals are herbivores. Herbivores eat plants. 
Cattle, horses and sheep are herbivores that eat grasses. Most of their teeth are at the side, inside their cheeks.
Watch a herbivore eating grass.
It pulls up the grass with its incisors, then grinds it up with its strong molars.
Beavers, rats and squirrels belong to a smaller group of herbivores called rodents.
Rodents gnaw their food. They have very large incisors for tearing bark from trees, or shells off nuts. Their front teeth never stop growing, so despite all the chewing, the teeth are never worn down.

Meat eaters

Some mammals are carnivores. Carnivores eat the flesh of other animals. 
A carnivore has teeth all around the front of its mouth. Some carnivores, like lions and foxes, use their incisors and canine teeth to stab and hold their prey.
Then they crush the meat and bones with their molars.

Plant and meat eaters

Mammals that are omnivores eat both plants and animals. 
Human beings are omnivores. 
So are bears and animals like hogs and opossums. Omnivores have teeth all around the front of their mouth—incisors for biting and cutting, canines for tearing meat, and close-set molars for chewing plants.

Insect eaters

Animals that eat mainly insects are called insectivores. Anteaters and hedgehogs are insectivores. 
Some insectivores have weak teeth, and some don’t have any at all. They lick up ants and termites with their long, sticky tongues.

The giant anteater of South America eats only ants and termites. Its tongue, which can be as long as 2 feet (60 centimeters), is covered with a sticky substance so that the insects stick to it.

What is a bird and what are the different kinds of birds?

Wherever we go in the world, we will see birds.
Scientists have named about 8,600 different species of birds.
Some species live in forests, while others live on grasslands, in deserts, on mountaintops or on uninhabited islands.
Some live near human beings—around farmlands and in cities.
Birds are the only animals with feathers.
All birds have wings but not all of them can fly.
A flying bird can travel faster than any other animal.

What are the different kinds of birds?

The kind of food that birds eat varies from one group of birds to another.

Birds of prey, such as eagles and hawks, catch mice, lizards, snakes, and other small animals. Some even catch fish.
The bald eagle uses its claws to snatch fish from the water while flying.
Birds of prey have sharp, curved beaks that can tear flesh.
Owls hunt at night and catch farm pests like rats and mice.

Swallows, martins, and swifts have large mouths adapted to catching flying insects. 
Their long, curved wings help them to fly fast, and to twist and turn in the air.

Hummingbirds are tiny birds that feed on nectar from flowers. 
They have a long, slender beak and a long tongue.
Hummingbirds are skillful fliers and can hover in front of a flower for several minutes.
Some can even fly backward!

Ostriches are the largest living birds. 
Sometimes, they grow as tall as 8 feet (2.4 meters).
An ostrich is too big to fly, but it can run as fast as 40 miles (64 kilometers) an hour, using its wings to balance itself.

 Penguins lost the ability to fly millions of years ago. 
They use their wings as flippers for swimming in the water.
On land, penguins walk or slide along.

Gulls and terns are common seabirds living mainly on fish. 
They have a strong, hooked beak.

 Macaws live in the forested areas of Central and South America. 
They eat nuts, seeds and fruit, using a short, arched beak.

How do birds breed?

All birds hatch from eggs.
Usually, the female lays her eggs in a nest built by herself or her mate, or both.
Baby birds may stay in the nest for weeks after hatching.
The parent birds feed and protect the young birds until they can look after themselves.

Reptiles - Lizards and snakes, crocodiles and alligators, turtles and tortoises - What are reptiles?

Lizards and snakes, crocodiles and alligators, turtles and tortoises—all these vertebrates are reptiles. 
Reptiles have dry skin covered with scales.
They breathe air through lungs, and most species lay their eggs on land.
The eggs of some reptiles have leathery shells.
Others are hard, like birds' eggs.

Lizards and snakes

There are nearly 3,000 different species of lizards.
Lizards like to live in hot places.
A lizard can survive the heat of the desert because its scaly skin keeps the moisture inside its body.
Most lizards have eyelids that close, ears on their head, a long tail, and four legs.
A few lizards, such as "glass snakes" and slow worms, have no legs.
There are almost as many species of snakes as there are species of lizards.
Snakes have no legs and no eyelids, and their ears are inside their head.
Their eyes are protected by transparent scales.
Most snakes live in warm places, but some can live in colder climates.
Most snakes swallow their prey— including frogs, rats, fish, and birds—alive.

The crocodilians

Alligators and crocodiles belong to a group of reptiles called crocodilians. 
They all live in or near water.
Most live in tropical countries, either in freshwater rivers and lakes, or in the low-lying areas nearby. Crocodilians have long snouts, strong jaws and webbed back feet.
Small crocodiles eat fish but bigger ones can eat quite large animals, including turtles.
A big crocodile can kill a human being with one lash of its tail!

 Turtles and tortoises - Reptiles with shells

Turtles and tortoises are the only reptiles with shells.
They belong to a group known as chelonians. 
Turtles live on land, in fresh water, or in the ocean.
Tortoises live only on land.
Many turtles live for a very long time—some have survived for as long as 150 years! 
Female chelonians dig a hole in the mud or sand. Here, they lay their eggs, cover them and leave them alone to hatch.
When the young hatch, they dig their way out and search for food.

What is a fish and Where do fish live??

Fish are vertebrates that live in water. They first appeared on the earth about 500 million years ago and were probably the first animals to have a backbone. Scientists have given names to nearly 22,000 different kinds, or species, of fish, in many different colors, shapes, and sizes.
Most fish have a spine, or backbone, made of hard bone which snaps if it's bent. These fish are called bony fish. Sharks and rays have a spine made of a tough, rubbery substance, called cartilage, which stretches like elastic. These fish are called cartilaginous fish.
Most fish breathe through a part of their body called gills. Gills enable fish to take in oxygen from the water. Most fish have skin covered with scales. These are thin, bony plates that form a protective covering. Nearly all fish have fins to help them swim. A fish uses its muscles to move its fins.
The smallest fish in the world is the pygmy goby. It lives in the Philippines and, when fully grown, is only 1/2 inch (13 millimeters) long. The world's largest fish is the whale shark, which may grow up to 60 feet

Where do fish live?
More than half of all known species of fish live only in the sea. These are called saltwater, or marine, fish. The porcupine fish is a marine fish. Most other species of fish live only in fresh water—in lakes, rivers, and streams. The sturgeon is the largest kind of freshwater fish.
The salmon is an unusual fish because it spends part of its life in fresh water and part in salt water. Young salmon hatch in freshwater streams before swimming to the sea. Female salmon swim back to the stream where they were born to lay their eggs.
Did you know that some fish can survive out of water? The walking catfish can walk over land to reach water if its own stream or lake has dried up. It pushes itself along the ground with its tail and front fins. Most species of lungfish can live for months in dried-up riverbeds.