Being a daemon/non-daemon thread, and the thread priority are unrelated concepts. So a daemon can have high or low priority, as can a non-daemon thread.
Of course, often it is true that daemon threads have low priority, because they perform non-critical operations (if they didn't, they should not be daemon threads to begin with).
It is generally recommended that the priority of threads not be changed by the setPriority method (which means it should not be changed at all), and that it should be left to the JVM which thread to schedule. [ July 19, 2007: Message edited by: Ulf Dittmer ]