What are 2 reasons that both cnidarians and poriferans are considered simple animals?

They are heterotrophic

They can move from one place to another

Explanation:

Poriferas include mainly sponges while Cnidarians consists of jelly fish, sea anemone etc.

Poriferas and Cnidarians swallow organic matter in the water as source of food.

Both of them also move although poriferas are only motile in its larva phase and non motile in adult phase while Cnidarians are motile in all phases of life.