Redear sunfish spawn from spring to very early fall. The males develop nests in silt, sand, or soft mud. These nests are developed with each other in colonies in shielded, shallow locations near the coast. The ladies deposit the eggs which hatch out within two to 4 days. These eggs are guarded by the men for several days. The young eat zooplankton.
As bottom feeders, their favorite food is snails, but they also consume other shelled animals. Their thick, hard teeth permit them to crush the skeletal systems of shelled pets. These teeth go to the back of their mouths, and also allow them to run like a nutcracker by crushing the coverings of snails, hence the nickname, "shellcracker". They can even open up little clams. They will additionally eat larvae, fish eggs, and crayfish. Due to its specific meals particular niche, Redear sunfish could live in lakes without contending for the same food of fish that like area eating. As well as because snails could spread out condition, and since snails are among Redear's favorite foods, these fish are relied on in lake management projects to regulate snails.