Inclusion dependencies express subset-relationships between databases and are thus important indicators for redundancies between databases. In the context of database integration, it can help to solve a very common and difficult problem: "discovering redundancies across crisp databases". Inclusion dependencies in crisp databases are well known and some related work can be found in the literature, however, the idea of fuzzy inclusion dependencies in fuzzy relational databases is new that we have introduced in This work and derived the inference rules on such dependencies. An algorithm has also been proposed for the discovery of FIDs that may exist between two given fuzzy relations stored in one or more fuzzy relational databases.