Bully birds are usually larger than most common songbirds, so either utilizing smaller feeders they can't find footing on, or wire-caged feeders that keep larger birds out can be a good tactic. Temporarily switching to feed they don't prefer can also help. For instance, both safflower and nyjer (thistle) seed are disliked by crows, grackles and blackbirds, but enjoyed by cardinals, chickadees and more. Lastly, cast-off seeds below hanging feeders can draw in flocks of bullies. Cleaning up fallen seeds regularly or placing a deep container like a plastic garbage pail beneath a feeder to catch them as they drop can help keep undesirable birds away.