Which Animal Goes There? – Animal Classification (JHARVNC)


Participants learn the differences between living and nonliving things, major characteristics of life and classifying animals based on physical characteristics using guides and keys.

Grade Level:

K - 12

Recommended Setting:

Classroom or multi-purpose room

Outdoor Activity:



Janet Huckabee Arkansas River Valley Nature Center, Fort Smith


Education Program Coordinator, 479-452-3993


30 - 45 minutes

Suggested Number of Participants:



  • Be able to list the characteristics or themes that differentiate living and nonliving things
  • Explain and name animals that are invertebrates and vertebrates
  • Differentiate among classes of animals (reptile, amphibian, bird, mammal, fish)
  • Identify the five reuirements for sustaining animal life (food, water, cover, space and arrangement)

Key Terms*:


Asexual reproduction


Cell theory








Sexual reproduction


*See glossary for definations


Dichotomous keys for older participants

Note cards

Photos of uncommon Arkansas animals


Living Things
It is not always easy differentiating among living, dead and nonliving things. Prior to the 1600's, many people believed that nonliving things could spontaneously turn into living things. For example, it was believed that piles of straw could turn into mice. There are some general rules when deciding if something is living, dead or nonliving. Listed here are the six rules scientists use:

  1. Cells – All living things are made of one or more cells. This is called the cell theory. Different types of cells have different jobs within the organism. Each life form begins from one cell, which then will split. These cells split, and so on. After several times of this, cells change. At this point, they construct the final organism with some cells, for example, as the eyes, some as the heart, etc. The only arguable exception to this is viruses. They are not composed of cells but are said to be living.
  2. Organization – All living organisms have complex organization patterns. They arrange themselves on very small levels, grouping like things together. On larger levels, they become visible. This also relates to differentiation as the cells are organized once they change to what they’ll be in the final organism.
  3. Energy Use – All organisms use energy. The sum of the chemical energy they use is called metabolism. This energy is used to carry out everything they do. Autotrophs (plants) use energy from the sun for photosynthesis, to make their own food (glucose). Heterotrophs (animals and humans) must ingest food for this purpose.
  4. Homeostasis/response to environment – All organisms have stable internal conditions that must be maintained to stay alive. These include temperature (thermoregulation), water content and heartbeat which require a certain energy level at all times. Humans must then ingest food regularly. Not all conditions are for the body to maintain itself, though most are.
  5. Growth – All organisms grow and change. Cells divide to form new, identical cells. Differentiation happens, as well, when cells mutate into other types of cells, making a more complex organism. Organisms growing, changing and becoming more complex are part of development. Single-celled organisms grow as well, but they will only become slightly larger, which is nearly immeasurable.
  6. Reproduction – All organisms reproduce to continue the species' life. This means combining genetic information (in sexual reproduction) or splitting into two organisms (in asexual reproduction) to create another of the same species. In sexual reproduction, the new organism will have some characteristics from the mother and some from the father. It may look like either of them or it may not. In asexual reproduction, the new organism is an exact copy of the first. Sometimes, not every member of a species is able to reproduce. As long as others are capable (which we know they are if they still exist today), then it does not threaten the species. Mules are one example, but they are an anomaly.

Animals have a few characteristics that all share, which distinguish them from plants. They are multicellular, consume food, have movement and embryonic development

  • Classifications
    • Invertebrates
      • Sponges – live in water and have pores or holes through which water flows
      • Jellyfish – live in water and have sac-like bodies and stinging cells
      • Flatworms – long, flat, ribbon-like bodies, most are parasitic
      • Roundworms – long, thin, tube-like bodies without segments, most are parasitic
      • Segmented worms – long, tube-like worms with segments, the simplest organism with a nervous system
      • Mollusks – soft-bodied, most have shells
      • Starfish – have similar arms or rays and tuber feet
      • Arthropods – have jointed legs, an exoskeleton and segmented bodies
    • Vertebrates
      • Mammals – breathe air with lungs, warm-blooded, body covered with hair or fur, young develop in mother’s body, produce milk to feed young
      • Amphibians – live part of life on land and part in water, can breathe in water and on land, cold-blooded, smooth-skinned, lay jelly-like eggs in water
      • Reptiles – live mostly on land, breathe air with lungs, cold-blooded, body covered with scales, lay soft-shelled eggs
      • Birds – live on land, breathe air with lungs, body covered with feathers, lay eggs, have hollow lightweight bones
      • Fish – live in water, obtain oxygen through gills, cold-blooded, usually covered with scales, lay eggs


  1. Seat participants on the floor and introduce the speaker.
  2. Ask participants if certain objects are living or nonliving. Explain that trees are living, as are snakes or lizards, but the materials in stuffed animals or wood tables are no longer alive. Objects such as glass windows and concrete are not living. Tell participants that we will be able to decide whether something is living or nonliving and classify the type of animal.
  3. Give participants note cards with “living things,” each of the six rules, “animals,” “invertebrates” and “vertebrates.” Have each participant line up in front of the room and read the back of each card.
  4. Have pictures of less common animals in Arkansas (salamanders, macroinvertebrates, etc.) with descriptions about the animals’ physical characteristics and have participants determine if the animal in the photo is living or nonliving, vertebrate or invertebrate and classify the animal in the photo.
  5. Wrap up with review of the rules that determine if animals are living. List the types of animals and have participants determine if they are invertebrates or vertebrates as well as classifying the types of invertebrates we have in Arkansas.  Remind participants that all animals provide for the environment in some way. Encourage them to be aware of the consequences of destroying habitat, littering, etc.


Provide older participants with dichotomous keys for animals and have them determine which animals fit into each grouping.


  • What are cells and why are they so important? What does the cell theory say about how different kinds of cells work together?
  • What determines whether something is living or nonliving and the difference between living plants and animals?
  • What are the main classifications of vertebrate animals?
  • What is the primary difference between vertebrates and invertebrates?


  • Sealander, John A. Sealander and Gary A. Heidt. Arkansas Mammals: Their Natural History, Classification, and Distribution. University of Arkansas Press.
  • Sutton, Keith, ed. Arkansas Wildlife: A History. Arkansas Game and Fish Commission. University of Arkansas Press.


Amphibian – any cold-blooded, egg-laying vertebrate of the class Amphibia having gilled aquatic larvae and air-breathing, semiterrestrial adults; examples are frogs and toads, newts and salamanders, and caecilians

Asexual reproduction – reproduction with no fusion of male and female sex cells (gametes); for example, vegetative reproduction or budding; formation of new individuals from the cell(s) of a single parent

Bird – any warm-blooded vertebrate of the class Aves, having a body covered with feathers, forelimbs modified into wings, scaly legs, a beak and no teeth, and bearing young in a hard-shelled egg
Cell theory – states that cells are the basic units of structure in all living organisms and all cells come from the reproduction of existing cells

Fish – any of three classes (jawless, cartilaginous and bony) of cold-blooded vertebrate animals living in water and having fins, permanent gills for breathing, and, usually, scales

Homeostasis – ability of a system or organism to maintain equilibrium by regulating its internal environment when faced with external changes

Invertebrate – an animal, such as an insect or mollusk that lacks a backbone or spinal column

Mammal – any of a class of higher vertebrates, including man, that produce milk for their young, have fur or hair, are warm-blooded and, with the exception of the egg-laying monotremes, bear young alive

Multi-cellular – having many cells

Reproduction – biological process of all known life by which new plants and animals are produced; may be sexual or asexual

Reptile – any cold-blooded, egg-laying, air-breathing vertebrate of the class Reptilia, including turtles, snakes, lizards, crocodilians, amphibians, tuatara and various extinct members including the dinosaurs

Sexual reproduction – Reproduction involving the fusion of the female egg and male sperm, which potentially develops into genetically distinct offspring

Thermoregulation – ability of an organism to keep its body temperature within certain boundaries, even when surrounding temperature is very different