They tend to come out when the weather warms. What exactly they do this time of year, I don't know, but they tend to be easiest to catch when water temps get around 68 or 70 (which is about when the pompano get active as well...probably not a coincidence).
I usually just catch them with my hands. It takes a little practice, but not all that hard.
Lately, I've become somewhat lazy and have started buying the "GULP!" brand artificial versions. They last on a hook a lot longer and you don't have to cut into your beer drinking time to catch the live ones.