Inherits Triggers or Rules

Hi everyone.

I try to make inherited trigger for table on PostgreSQL.

I want that when I create a table which inherits from another that trigger
are inherited. I try to make a rule on INSERT on the Pg_inherits but my
function isnt fired.

Can I create trigger or rules on tables from the system catalogs ?
Is there a command to fire a function when data are entry in System Catalogs
tables ?

I Hope you can help me.

Thanks .

Jérôme Chochon