I have not checked water temps around IC recently, but I am sure they are in the upper seventies, so the catfish, channel and flathead both, should be spawning now. When spawning, catfish build nests in logjams, rip-rap, and other such places, and stay right on their nests to guard them. If you happen to drop a bait right in front of a nest they will crush it, but otherwise the catfish spawn is not a productive time to fish for them. Some catfish no doubt start spawning early or late, or skip it entirely for whatever reason, as it always possible to catch some during spawning time, but the overall number of adult fish caught is lower.
I am not a die-hard catfish guy, so take all this with a grain of salt (I never fished for channel cat at all until I moved to Iowa), but the spawn seems to wind down in early July, as the channel and flathead fishing picks up in southern Iowa at that time, and is really going by the end of the month.