One of the key problems of database systems is the collection and maintenance of data. Web agents can assist by automatically locating and extracting information from the Web and updating the database accordingly. At the same time, it is important that such Web agents be dynamically configurable, have knowledge about other agents cooperating in a task, maintain a history of their actions and manage the information that they retrieve so that it is easily accessible when required. It is therefore sensible that the operation of such Web agents for databases is itself controlled by a database. We will present various example application systems we have developed that combine databases and Web agents. This has led to a general architecture comprising agent and database components and we describe how this has been used in an application to maintain a database about researchers and their publications.