After dark, I generally pick up a few cats in the same places I'd been catching bass during the day, namely weed edges, drop-offs and such. I've taken quite a few on poppers but mostly on streamers with lots and lots of motion. During the day you can still find them but they will be on the deep side of the drops then and you have to go down a bit more to get them. Farm ponds are an exception as I've often caught cats cruising the shallows during full daylight. I think the darker water is the key there as most the ponds I fish stay pretty dingy.
Great fish, Dave!
If it swims and eats, it'll eat a fly.