live in the air—
1. (of birds) spend part of their lives in the air:
- We have birds that live in the air, those that live on the earth and those that live in the sea.
2. (of viruses, etc.) be able to survive in the open air:
- Microorganisms can live in the air, on land, and in fresh or salt water environments.
Note: The expression does not correlate in meaning with the phrase live on air—survive on very little food:
- Annick is one of those young Parisians who live on air and use the cafes as living rooms.
live in the open air—
1. said of people not living inside a house or building:
- The natural savages may live in the open air, and subsist on the ordinary products of the earth.
2. spend most of the time outdoors rather than indoors:
- Large orange trees with their dense shade shut out the sun so that we can sit, and walk, and live in the open air.