Straight safflower seed. Attracts cardinals, chickadees, house finches, and rose-breasted grosbeaks. The big advantage of safflower is that starlings, grackles, and brown-headed cowbirds WILL NOT eat it. We highly recommend having a dedicated safflower feeder, especially if you want to attract cardinals, as it will provide them a feeder to go to where they don't have to compete with as many birds.