What insects are in a tide pool?
Insects don't do well in salt water, so none. There might be crustaceans, however, in the form of aquatic isopods (pillbugs). Also barnacles - these are crustaceans!
Why does the tide pool need to change during high tide to keep the inhabitants of the tide pool healthy?
How is the entire noun clause used in the sentence. The plan was that a visit to the tide pool would be during low tide?
Michael Rigsby has written: 'A quick field guide to tidepools of the Pacific coast' -- subject(s): Tide pool plants, Coastal ecology, Tide pools, Guidebooks, Habitat, Tide pool animals, Tide pool ecology 'Mating games' -- subject(s): Aquatic animals, Behavior, Reproduction, Sexual behavior in animals 'Monterey Bay Aquarium' -- subject(s): Marine animals, Monterey Bay Aquarium