Unusual collective nouns

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Across
  1. 2. a great number of bees
  2. 4. a large group of people or things of a particular kind
  3. 5. large group of social fish
  4. 7. the habitat where a colony of molluscs thrives
  5. 8. a group of caterpillars
Down
  1. 1. a large group of hamsters
  2. 2. A small grove of trees
  3. 3. A group of iguanas
  4. 4. a group having a common nature or origin
  5. 6. it can be applied to reeds, moss or seaweed