I've found corn, powerbait, and sometimes plastics in their stomachs. they are full of mysis shrimp most of the time though. kept 1 this ice season and it had a perch in its stomach. This lake (blue mesa) just started getting a few perch in it within the last couple of years, and it is the only laker lake with perch in it in Colorado (to my knowledge). Hopefully though, the lakers will start eating perch so they don't take hold. They could make matters worse than they already are at blue mesa (aka big blue).