I've seen a lot of big flat heads caught when the crappie are spawning. They seem to be in the shallows with them. After May, we start fishing for them at night through the summer months. We use live perch for them. Not to say you can't catch them in the winter months, just look for deep water with big logs or concrete/rocks caves. They seem to like to hide where the water is warmer and deep. With todays electronics, it makes locating them easier in the winter months.