Through these worksheets your students will read short passages about interesting ways that different animals have evolved in order to survive, whether that is through blending into their environments, storing food over long periods, the ability to regrow lost limbs or extra teeth, the differences between warm-blooded and cold-blooded species, and more. Two different answer sheets-one multiple choice and one short answer-are provided for each passage. Answer keys are provided for each sheet. Fun Fact: some scientists believe that certain animals' ability to regenerate holds the key to reversing the aging process in humans.
Print Animal Worksheets
Click the buttons to print each worksheet and associated answer key.

Why Do Camels Have Humps?
A camel is the only animal that has a hump. Some people believe this hump holds water but actually the hump is a storage site for fat.

Multiple Choice Questions
The hump is necessary to the camel's survival in the desert. As the camel travels through the desert where food and water are scarce, it draws energy from the fat stored in the hump.

Short Answer Questions
The idea that a camel can store large amounts of water is not completely untrue.

Why Do Animals Shiver? - Reading Worksheet
In cold weather there are a few ways a mammal can regulate their body temperature.

Multiple Choice Questions
When we think of shivering we usually think it is just something that happens when an animal is cold. While this is true, shivering also has an important function.

Short Answer Questions
Muscles around the organs of the animal begin to shake in small movements. This shaking or shivering uses energy and creates warmth in the animal.

Which Animal Can Live the Longest? - Reading Passage
Recently, researchers at Bangor University in Wales journeyed to the Northern coast of Iceland. Their mission was to get information about changes in the marine environment.

Multiple Choice Questions
Instead they encountered a clam that took the title for the longest living animal.

Short Answer Questions
After scientists cut through the clams' shell to count the growth rings, it was determined that this particular clam was between 405 and 410 years old.

Can Animals Regrow Body Parts? - Reading Passage
Some animals have the ability to grow a lost or damaged body part back to its original form.

Multiple Choice Questions
Salamanders can also regenerate limbs. Often if you try to grab a salamander by the tail you will find that the tail stays in your hand and the salamander takes off.

Short Answer Questions
Not all living things can regenerate parts. In humans the stump of an amputated part would just heal over.

Do Animals Take Baths? - Reading Passage
Regular cleaning keeps their fur, feathers, or scales clean and in good condition. Removal of insects, dead skin cells, oil and dirt are common reasons for an animal bath.

Multiple Choice Questions
Birds commonly take water baths and use the water and their beak to smooth or clean their feathers.

Short Answer Questions
Many animals also participate in social cleaning or grooming for the same purpose of removing dirt, oil and foreign objects Primates are the perfect example of this type of cleaning and grooming.


Multiple Choice Questions
Warm blooded animals need to keep the inside of their bodies at a constant temperature.

Short Answer Questions
In cold environments the cold blooded animal is sluggish and slow moving because of their low body temperature.

Why Do Sharks Keep Swimming? - Reading Passage
Sharks are recorded to date back more than 420 years ago, even before the time of the dinosaurs.

Multiple Choice Questions
Most fish have muscles and other equipment to pump water through their mouth and over their gills without moving.

Short Answer Questions
Unlike most fish, sharks have no air bladder. Fish are able to use their air bladders to float easily in the water.

How Do Fish Float? Reading Passage
What makes a fish float in water? The simplest answer to this is air.

Multiple Choice Questions
Fish use their air bladders to rise or sink in the water. If a fish wants to travel or rest near the bottom of a body of water it simply lets air out of it air bladder.


Why Do Animals Look Like Where They Live? - Reading Passage
Animals need every advantage they can get in order to survive and reproduce. This fact has caused many animals to evolve special adaptations to suit their individual needs and help them to find food or hide from predators.

Multiple Choice Questions
Many animals such as deer and squirrels have a brownish color that matches the brown of the trees and soil.

Short Answer Questions
The walking stick is a perfect example of this. A walking stick is an insect that looks like a small twig or stick.

Why Do Elephants Have Big Ears and Giraffes have Long Necks? Passage
Over the years animals have evolved and developed adaptations that are unique to the animal’s environment and situation.

Multiple Choice Questions
The elephant has some of the largest ears of any animal. Is this simply to help them hear well?

Short Answer Questions
The giraffe also has a unique adaptation. Its long neck gives it the title of the tallest animal.
What You Need To Know About Animals
Animals are living things that go about eating plants or other animals for food. Their bodies have senses (hearing, seeing, smell) that allow them to react to changes in the things around them. Sense can help them find food, find a warm place to sleep, or just get away from danger. There are thought to be just under nine million different animal species out in the world. There are animals that live in the woods, underwater, in a tree, in a cave, and even in your own home. That is right you are an animal, we all are. Animals do all kinds of crazy things that we do not even realize. Snails can sometimes sleep for up to three years. They do this to conserve moisture during very dry periods. Elephants are the only known land animal that cannot jump. This is because elephant leg bones are positioned downwards and have zero spring to push off the ground. There are millions of animals worldwide. There are so many things to know about them, and I'm about to share a few.
A fact about animals that you need to know is that they all belong to one kingdom and share common characteristics. They are further categorized into phyla or other types, such as sponges and chordates. Each phylum has a unique set of uniting traits.
The Characteristics That Make an Animal an Animal
Organisms are classified into kingdoms, orders, and other taxa based on their traits. Each taxon has a specific set of qualities that unite its members through similarity. Thus, members of the kingdom Animalia all have similar characteristics.
An organism is considered to be an animal if they have the following traits:
- Multicellular. They are composed of more than one cell.
- Eukaryotic. They have membrane-bound organelles, including a nucleus that stores genetic material like DNA.
- Heterotrophic. Unlike plants, animals cannot photosynthesize food and have to consume other organisms for nutrients.
- Lack of cell walls. Fungi and plants have rigid cell walls, which are distinctly absent in animals.
- Diploid. Animal cells are diploid or contain two sets of chromosomes, except for gamete cells, which only have one set.
Another notable animal trait is mobility. However, since not all animals are mobile, it isn’t a defining trait.
Different Types of Animals
Kingdom Animalia is subdivided into various groups with their own set of characteristics.
Each animal belongs to a particular phylum, which may be further subdivided into orders, families, classes, and other taxa. For this article, I’ll briefly discuss the main phyla of animals.
Porifera
Sponges belong to the Phylum Porifera. They are the most basal of all animals, and many people are surprised to learn that they’re classified as animals at all.
Although they lack true tissues and organs, they do have specialized cells. They also have asymmetrical bodies, flagellated cells, and pores.
Cnidaria
Cnidaria is made up of:
- Jellyfishes
- Sea anemones
- Corals
These soft-bodied creatures are often aquatic and are known to sting. They also have a radially symmetric body and two germ layers (diploblastic).
Platyhelminthes
Flatworms, tapeworms, and flukes make up Phylum Platyhelminthes. They are the simplest triploblastic animals. These organisms are:
- Hermaphroditic
- Bilaterally symmetrical
- Might be parasitic
Nematoda
Roundworms are also called nematodes because they belong to Phylum Nematoda. Nematodes are similar to arthropods in that they have exoskeletons and undergo shedding. They also have symmetrical and unsegmented bodies.
Mollusca
Snails and clams are a few familiar examples of the very diverse Phylum Mollusca. Some of these mollusks have shells but others, like slugs and squids, do not. These soft-bodied creatures vary in appearance and habitats. Other examples include:
- Octopi
- Cuttlefish
- Giant squids
Annelida
Annelids are also worm-like or vermiform organisms. Examples of annelids are earthworms, leeches, and the less well-known ragworms. They have segmented bodies and usually have a cuticle layer. They are usually broken into two categories: ringed worms and segmented worms.
Arthropoda
Insects, crustaceans, centipedes, and spiders all belong to one group: Phylum Arthropoda. It is the most diverse and numerous out of all animal phyla. Arthropods are symmetrical, segmented creatures that appear in all forms and inhibit varied habitats. It seems odd to imagine lobsters and spiders in the same phylum, but they are.
Echinodermata
Sea stars are part of Phylum Echinodermata. Other echinoderms include sand dollars, sea cucumbers, and sea urchins. They only live in marine environments. They have a unique water vascular system to survive in seas and oceans. They cannot survive on land or in freshwater environments.
Chordata
Humans, vertebrates, and cephalochordates belong to the phylum Chordata. We are distinct for having the following features:
- Notochord
- Hollow nerve cord
- Post-anal tail
- Pouches or slits in the pharynx
- Thyroid gland
These characteristics may not be present in adults, but they should exist at some point in our lives.
Final Thoughts
There is great diversity to be seen in the animal world. Creatures of all shapes and sizes reside in varying habitats across waters, land, and even air. Each animal has its wonders and knowledge waiting to be discovered by you. This article only articulates a few of the million things you need to know about them.