It is a proverb which means that you have to face the consequences of your mistakes or bad deeds.
Jill: Emily found out that I said she was incompetent, and now she won’t recommend me for that job.
Jane: The chickens have come home to roost, I see.
So if you say that chickens are coming home to roost, you mean that bad or silly things done in the past are beginning to cause problems.
Example: There was too much greed in the past, and now the chickens are coming home to roost with crime and corruption soaring.
In Spanish we say “pagar las consecuencias”