Some of the key features that define Mammals are a combination of fur and mammary glands. Some of the largest animals that have ever existed have been mammals. The most intelligent animals in the world are mammals, including humans. See the mammals that we include in our Workshops
Reptiles are found in every continent except Antarctica. As they cannot maintain their own body heat, they rely on heat from the sun to warm up. Amphibians are closely related to reptiles except most amphibians have a water-based laval stage, like frogs start as tadpoles.
An invertebrate is any animal that doesn’t have a backbone like insects, spiders, crabs and snails. 97% of the animals on this earth are invertebrates and about 80% of them are insects.