Animal Groups & Habitats — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. A baby frog starts life as a tiny tadpole in the water.
A penguin's wings are short and stiff like flippers, so instead of flying through the air, they use them to swim through cold water.
2. A caterpillar changes into a butterfly inside a chrysalis.
Having hair on the body and feeding milk to babies are two of the main rules for being a mammal, so a horse fits right in the mammal group.
3. Baby birds hatch from eggs that their mother keeps warm.
Toads and newts both start life in water and move to land as they grow up, which makes them amphibians.
4. A baby cow is called a calf.
Fish must stay in water because their gills only work underwater, pulling oxygen out of lakes, rivers, or the ocean.
5. Mammals feed their babies milk from their bodies.
Insects have six legs, but spiders have eight, so scientists put spiders into their own group called arachnids.
6. A baby dog is called a puppy.
Parrots have feathers, beaks, and wings, putting them in the bird group — and the bright feathers help them hide in leafy trees.
7. A tadpole grows legs before it can hop on land.
Even though crocodiles live mostly in water, they are reptiles, and reptiles always lay their eggs on land where the babies can grow safely.
8. Most reptiles lay eggs on land that have tough shells.
Dolphins are mammals, not fish, so they must swim to the surface and take in air through a blowhole on the top of their heads.
9. A baby cat is called a kitten.
Ladybugs and grasshoppers each have six legs and three body parts, which fit the rules for joining the insect group.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each adult animal to the name for its baby.
Bear
→ Cub
Lamb
Hen
→ Chick
Foal
Horse
→ Foal
Chick
Sheep
→ Lamb
Cub
Each group has its own key features: fish use gills, insects have six legs, birds have feathers and beaks, and mammals have fur and feed milk to their babies.