Does it have feathers?
Yes : Then it is not a mammal. It is a bird.
No : Then it may be a mammal.

Does it have scales?
Yes : Then it is not a mammal. It is a reptile.
No : Then it may be a mammal.

Does it have fur or hair?
Yes : Then it may be a mammal.
No : Then it may not be a mammal. But it may be a hairless mammal.

Does it have either four legs or two arms and two legs?
Yes : Then it may be a mammal.
No : Then it is not a mammal.

Does it have nipples?
Yes : Then it is a mammal.
No : Then it is not a mammal.

Does its exhibit have to be kept warm?
Yes : Then it is probably not be a mammal. It is probably a reptile.
No : Then it may be a mammal.

Does it have a beak or a bill?
Yes : Then it is probably not a mammal.
No : Then it may be a mammal.

Does it have hoofs?
Yes : Then it is a mammal.
No : Then it may not be a mammal.

Does it stay under water?
Yes : Then it may not be a mammal.
No : Then it may be a mammal.

Does it have ears that we can see?
Yes : Then it may be a mammal.
No : Then it may not be a mammal.

Can it fly?
Yes : Then it may not be a mammal. It may be a bird.
No : Then it may be a mammal.

Does it roar?
Yes : Then it may be a mammal.
No : Then it may not be a mammal.

Does it have fins?
Yes : Then it may not be a mammal. It may be a fish.
No : Then it may be a mammal.

Does it have more than four legs? Yes : Then it is not a mammal.
No : Then it may be a mammal.

Does it have wings?
Yes : Then it may not be a mammal.
No : Then it may be a mammal.