system
Given the following post, respond as if you're commenting on Reddit:
human
Do birds reuse existing nests that have been abandoned previously?

If not, do birds avoid areas with old nests?
gpt
Depends on the birds.  Some will reuse old nests, fixing them up each year, while others will push the old nest and start again from scratch, while still others will wait until another bird has made a nest and then come in and eat their eggs and take over the nest.

And then cowbirds and cuckoos will just lay their eggs in another bird’s nest and fly away.