divers are whales

At the aquarium on chol hamoed, I was talking as we walked with ER (age 4) about how different animals moved, with a focus on whale tails (up-down) and fish tails (side-to-side). I asked him to tall me what dolphins are. He guessed fish until the dolphin show. Then as we headed to the shark exhibit I asked him about sharks. He though they were whales too until he saw them swim. After that we went to the main tank to see the divers feed the big turtle and the fish in that tank. He took a look and said, "Mommy, divers are whales!"