postgresql has more DB connection in staging servers than production server

We have postgresql 9.5 where we use it for an application confluence. in staging and in production both max connection is same. But we see staging uses more connection than production e.g staging has 170 connection to DB and production has 105.where as staging is very rarely used. and among 170 connection 169 is idle. can any body explain this behavior where highly used Db has less used connection and rarely used application has more used connection.